Volume percentage calculator 114 M. This means there is 12 ml ethanol for every 100 ml of wine. This calculator is useful when mixing components by weight is preferred to mixing by volume. Convert decibels to percentages and back. Use this simple science calculator to calculate concentration of volume percent using volume of solute, total volume of solution values. This unit is used when mixing volumes of two solutions to prepare a new solution. Nov 24, 2023 · Percent Volume-FAQs 1. Solution: Assume a composite sample of unit mass (1g) and compute the volume, Weight of fiber, W f = 0. How do I calculate percent solution? You can calculate percent solution using one of two formulas: Mass-based: (mass of solute / mass of solution) x 100; Volume-based: (volume of solute / volume of solution If you know molarity as well as the molar mass and density, you can determine the percentage concentration via the following formula: Percentage concentration = (Molarity × Molar mass × 100)/ Density. We use the volume percent formula to Jul 25, 2023 · To calculate a percentage moisture content, subtract the dry weight from the wet weight, divide the result by the wet weight, then multiply by 100. You can also use this molarity calculator to find the mass concentration or molar mass. , weight over volume) concentration units such as pg/mL, μg/μL, mg/mL, g/L, etc. Thus we get the following equations for the volume fraction and volume ratio: Φ = C v CBM Calculator shows the occupied weight and volume percentage of products inside the selected shipping container. Because the volume units cancel out, percent by volume is a unitless quantity. Volume percent is defined as: v/v % = [(volume of solute)/(volume of solution)] x 100% Note that volume percent is relative to the volume of the solution, not the volume of solvent. CBM Calculator is a free utility to calculate Aug 17, 2023 · The Percentage Difference Calculator (% difference calculator) will find the percent difference between two positive numbers greater than 0. Mar 16, 2025 · Calculate the percentage of Pneumothorax Volume on Chest Radiograph based on Collins Method. Oct 3, 2024 · The conversion of decibels (dB) to percentage and vice versa is a useful calculation in various fields, especially in audio engineering, acoustics, and electronics. It will help you estimate the percentage of alcohol in any liquor based on its initial and final specific gravity. Weight by volume percent (w/v %) tells you the mass of solute in grams that has been added to a 100 mL solution. Ellipsoid Nov 15, 2024 · Example of Change in Volume Calculator. The volume fraction coincides with the volume concentration in ideal solutions where the volumes of the constituents are additive (the volume of the solution is equal to the sum of the volumes of its ingredients). To use the calculator, enter appropriate values in all cells except the two cells you wish to calculate. Mar 15, 2013 · Thus C w may be 50 percent solids by weight, whereas C v may be 15 percent solids by volume. 7 x A+ B + C] Using this calculator, you can calculate the volume percent concentration, also called the volume percentage of chemicals in mixtures and solutions. 13 → 13. The ABV of a drink is represented as a percentage of the full volume of the drink and measures how much pure alcohol it contains. With our tool, you need to enter the respective value for Volume of Solute & Volume of Solution and hit the calculate button. 2 inches: volume=1/3 × π × 4(0. Volume Calculator; 3. 13 ** Lastly, you can either move the decimal two places or multiply by 100. net's sole focus is to provide fast, comprehensive, convenient, free online calculators in a plethora of areas. What is Volume Percentage and its Formula? Volume percentage is the unit of measurement of the solution and is used to find the concentration of the solution. To calculate Volume Percent, you need Volume of Solute (V solute) & Volume of Solution (V sol). 4 milliliters of molecular chlorine. 625. How do you Calculate Percent by Volume? Percent by volume is calculated using the P = (Volume of Solute / Volume of Solution) × 100. 0001%. Percentage Calculator – Converts Volume to Percentages Many people develop formulas based on volume, adding ingredients until they get just the right texture and performance. Unraveling Size (NSFW): A great site to check for debunking tricks, myths and lies regarding the average dick size. If your calculator says Weight/volume percent is a measure of the concentration of grams of solute in 100 mL of solution. In principle, ABV is the number of milliliters of pure, unadulterated ethanol that can be found in 100 milliliters of a solution, at 20°C or at 68°F. Substitute the known values to calculate the molarity: molarity = 5 / (1. Mass percent to volume percent conversion is done by relating the mass, volume and density of phases and is represented as V 1 = M 1 *ρ 2 *100/(M 1 *ρ 2 +(100-M 1)*𝜌 1) or Volume percent of first phase = Mass percent of first phase*Density of the second phase*100/(Mass percent of first phase*Density of the second phase+(100-Mass percent of first phase)*Density of the first phase). 46) = 0. When you mix solutions, the volumes are not always additive, so volume percent is a good way to express concentration. Moisture Content Definition. Since this type of concentration is expressed as a percentage, the indicated proportion must Volume of Solution using Volume Percent calculator uses Volume of Solution using Volume Percent = (Volume of Solute/Volume Percent)*100 to calculate the Volume of Solution using Volume Percent, The Volume of Solution using Volume Percent formula is defined as the ratio of the volume of a component to the volume percent of the component in the mixture, multiplied by 100. Specific gravity is explained in our specific gravity calculator. Bea is now left with a right conical frustum leaking ice cream, and has to calculate the volume of ice cream she must quickly consume given a frustum height of 4 inches, with radii 1. Volume percent to mass percent of a phase in two phase mixture and is represented as M 1 = V 1 *𝜌 1 *100/(V 1 *𝜌 1 +(100-V 1)*ρ 2) or Mass percent of first phase = Volume percent of first phase*Density of the first phase*100/(Volume percent of first phase*Density of the first phase+(100-Volume percent of first phase)*Density of the second phase). Dec 5, 2023 · Variables: FV is the final volume after the decrease (cubic units) IV is the initial volume (cubic units) DR is the decrease rate (percentage) To calculate the final volume after a decrease, multiply the initial volume by one minus the decrease rate divided by 100. 05 M. This is particularly useful in chemistry, medicine, food science, and industrial processes, where accurate measurements of concentration are crucial. Feb 6, 2020 · Note that volume percent is relative to the volume of solution, not the volume of solvent. 6% weight percentage instead of 28% for ammonium hydroxide? 28% ammonia (NH 3) is equal to approximately 56. What is M/V Percent? M/V percent, or mass/volume percent, is a way of expressing the concentration of a solution. 2. Apr 9, 2005 · This calculator can be utilized to perform dilution calculations when working with parts per billion (ppb), parts per million (ppm), parts per thousand (ppt), parts per hundred (pph, %). How Mass Percent Calculator Works? Let’s see how you could calculate mass percent for any element or a chemical solution with the assistance of this percent by mass calculator. 15 grams of calcium azide, Ca(N 3) 2, in water. Click on the "Use Percent Volume Ethanol" button to switch to % Volume. Click here for more Density-Concentration Calculators. . Mass Volume percent calculator uses Mass by Volume Percent = (Mass of Solute/Volume of Solution)*100 to calculate the Mass by Volume Percent, The Mass Volume percent formula is defined as the ratio of the mass of solute that is present in a solution, relative to the volume of the solution, as a whole. For example, to calculate the mass percent of NaCl in water, divide the mass of salt by water and multiply by 100. Enter recipe name. 1. Jul 24, 2013 · Cv= concentration of solids by volume EXAMPLE: if the liquid has a specific gravity of 1. Specific Gravity (SG) is calculated with density of water 1000 kg/m 3 or 62. A percent solution expresses the concentration of a solute in a solution as a percentage of the total solution, either by mass or volume. Moisture content is defined as the percentage of the weight of a saturated object that is associated with water. In our example, this is 0. 2 × 1. It is the same concept as volume percent (vol%) except that the latter is expressed with a denominator of 100, e. , mass over volume) or weight per volume (i. Percent weight volume is commonly used in the preparation of solutions, particularly in the medical and pharmaceutical fields. Percentage concentration typically refers to the mass of solute per 100 units of solution, while molarity is defined as the number of moles of solute per liter of solution. Our product data reports the % ammonia and not the % ammonium hydroxide. This is the percentage of ethanol contained in a beverage. In this case, 2. It is similar to finding percentage which you can use to calculate the weight/volume percentage concentration (mass/volume percentage concentration). Volume percent ={ Volume of solute / volume of solution} x 100. Related Percentage Calculator Scientific Fraction Percentage Triangle Volume Standard Deviation Random Number Generator More Math Calculators. Interestingly, all of the other properties like strength, stiffness and so on all depend on the volume percentage of filler as well – more about that on this page. This updated calculator now includes Volume% Ethanol as a paramenter so it can now be calculated for or given as a value. Note that if you let V 1 = 2. How to use this density mass volume calculator. 50 versus 33. Clear and Free! Simple Calculator - A nice Simple Free Online Calculator. Easy to use and read. Many people are given a formula based on percentages. Directions: 1. Calculate a volume adjustment to reach a desired final concentration. 000001 or 0. Alcohol by Volume (ABV) The percentage of alcohol present in a finished beer, indicating its strength and potency. 1 MINERAL PROCESSING FORMULAS. Input: To calculate a percentage, you typically divide the part (the smaller value) by the whole (the larger value), and then multiply the result by 100. This is the size batch you want to make. As difficult is it may seem on the surface, converting parts per million (ppm) to % volume is actually very simple! Think of 1 ppm as 1/1,000,000 which equals 0. May 28, 2024 · Calculate the volume percent of a solution that is prepared by mixing 519. To calculate a weight/volume percentage concentration (mass/volume percentage concentration): Step 1: Write the equation: either w/v% = w/v × 100 or m/v% = m/v × 100 ; Step 2: Identify the solute and solvent (by name or chemical About Weight Volume Percent Calculator (Formula) The Weight Volume Percent Calculator is a helpful tool for calculating the concentration of a substance in a solution, expressed as a percentage. How to Calculate Percentage Decrease. This calculator converts percentage by weight or parts by weight to percentage by volume and also parts by volume. 01 liters. For example, alcoholic beverages often list the amount of alcohol in Oct 3, 2024 · The formulas to calculate the volume increase and the percentage increase are as follows: \[ \text{Volume Increase} = \text{Final Volume} - \text{Initial Volume These units are typically represented by ABV, or alcohol by volume. 25 × 3. Decibels are a logarithmic unit used to express the ratio of two values, commonly power or intensity levels, and converting them into percentages can help in understanding these Alcohol By Volume, most commonly known by its abbreviation ABV, is a standard unit of measurement that is used to calculate the percentage of alcohol (ethanol) in an alcoholic beverage. 4 liters. Aug 29, 2023 · Calculator Use. The calculator The percentage increase calculator above computes an increase or decrease of a specific percentage of the input number. The Percent Change Calculator finds the change between two numbers as a percentage. Assume density of fiber as 2. 55 g Volume fraction of fiber, V Calculator of percent solutions for electron microscopy research. The Density or Specific Gravity of each indivdual component is required. To calculate the percentage change in volume, the formula is applied as follows: Aug 6, 2024 · By mastering percent volume calculations, you can make processes smoother, reduce mistakes, and achieve great results in various tasks. This gives you the percentage value as a number between 0 and 100. Oct 3, 2024 · Percent Solution Calculator. ABV Formula The mathematical equation used to calculate alcohol content based on original gravity and final gravity. 5 2) = 10. Calculator for %AbV and EQUIVALENT VALUES: For more detailed instructions see Additional Information below. Calculating ABV involves using the original and final gravity readings in a specific formula. 90 ÷ 690 = . The choice between them depends on the nature of the solution and the precision required for the application. DB to Percentage Example Aug 6, 2023 · Q1: Why is the Percent by Mass/Volume Calculator essential? Answer: The Percent by Mass/Volume Calculator is a critical tool for any chemistry student, pharmaceutical expert, or laboratory professional. Volume percent (v/v%) is the volume of solute divided by the total volume of solution, multiplied by 100. Since this type of concentration is expressed as a percentage, the indicated proportion must With this density mass volume calculator, you are free to enter any two of these values, and the calculator will instantly calculate the third value. The calculator can convert between mass concentration and molar concentration. e. Volume % = (Volume of solute / Total volume of solution) × 100% Jul 4, 2022 · In the Volume (initial) field, proceed to enter the volume of the stock solution. Answer In order to calculate the mass/volume percent of a solution, each substance that is referenced in the problem must first be classified as a solute or a solvent. The percent solution calculator helps you find the mass by volume percentage of a solution, as well as the mass percentage and the volume percentage. Please be careful that the correct volume or weight units and the correct concentration expression (% Volume or % Weight) are used in your application. or. 2 and the concentration of solids by weight is 35% with the solids having a specific gravity of 2. Volume percent is additionally referred to as percent by weight or v/v%. Next, enter the desired concentration of the dilute solution. Our calculator is designed to use the % ammonium hydroxide. Currently, we have around 200 calculators to help you "do the math" quickly in areas such as finance, fitness, health, math, and others, and we are still developing more. Concentration Calculator and Concentration Converter The converter allows the user to convert between different ways of expressing concentration involving mass percentage,mass concentration(m/V), volume-volume percentage, molarity, normality, ppm, ppb and ppt. Enter total batch volume. Subtract starting value minus final value; Divide that amount by the absolute value of the starting value Nov 10, 2024 · Testicular Volume Percentile Calculator: Recommended website for calculating ball size. Apr 9, 2005 · Meant to be used in both the teaching and research laboratory, this calculator (see below) can be utilized to perform dilution calculations when working with solutions having mass per volume (i. LAST UPDATED: 2024-10-03 22:02:56. This calculator is useful when mixing components by volume is preferred to mixing by weight. DB to Percentage Definition. This is because these percentages refer to different amounts: 25% of 3. The solute is the Jul 17, 2019 · Online concentration of volume percent calculator . Jun 4, 2024 · To calculate the M/V percent, divide the mass of solute by the volume of solution and multiply the result by 100. 7 Find the fiber volume fraction and density of a composite with 45 weight percentage of fiber. It basically involves converting a percent into its decimal equivalent, and either subtracting (decrease) or adding (increase) the decimal equivalent from and to 1, respectively. The term volume ratio represents the ratio of the volume of solid to the volume of liquid. Scientific Calculator - A great Scientific Calculator. 1 Pulp Densities; 1. Then, ppm stands for parts per million, so 1ppm = 1/1,000,000. Mar 1, 2001 · This calculator can be utilized to perform dilution calculations when working with molar or percent (%) solutions using the formula C1V1 = C2V2, also known as M1V1 = M2V2. 2 × 36. Percentage difference is usually calculated when you want to know the difference in percentage between two numbers. Do you ever wonder how much of a substance is in a given volume? Let’s dive into the world of volume percentage calculations to find out! What is a volume percentage Aug 2, 2013 · Meant to be used in both the teaching and research laboratory, this calculator (see below) can be utilized to perform a number of different calculations for preparing solutions having mass per volume (i. It helps to know the strength of a drink based on the initial and final specific gravity readings. Jun 3, 2024 · The Percent by Volume Calculator compute the concentration of a solution by determining the ratio of the solute to the total solution volume. Pneumothorax Volume Percentage = 4. C H E M I C A L P E R C E N T C A L C U L A T O R Fill-in All Datafields:* This calculator includes the choice of expressing concentration in % Volume Ethanol. The density of a slurry can be calculated with the calculator below. Online Abacus - An Online Abacus! Teach numbers from 1 to 50 :-) Darts Calculator - Forget the maths, and play Darts! Maths Calculator - This Online Maths Calculator show the history of your sums Jul 20, 2022 · It is also known as volume percent (vol%) or % v/v. Calculator. Total volume of solution: mL: fL pL nL μL Nov 25, 2023 · The calculator below may be used when mixing two solutions, with molarity or percent (%) used for the concentration of the solutions. Author: Neo Huang. Volume percent is the volume of solute per volume of solution. In the final row, Concentration (final), the calculator will show you the final volume of the dilute solution. Define the concentration units of mass percentage, volume percentage, mass-volume percentage, parts-per-million (ppm), and parts-per-billion (ppb) Perform computations relating a solution’s concentration and its components’ volumes and/or masses using these units\ Express concentrations of solution components using mole fraction and molality Unlock the world of chemistry with our Mass Percent Calculator! Whether you’re a student, teacher, or researcher, this tool offers instant and accurate calculations, helping you understand the composition of mixtures effortlessly. Alcohol amount is usually expressed as a percentage of volume (% vol) that is not an unambiguous value without the temperature info (if not specified, it usually refers to The actual density of that composite is 1. It calculates the weight volume percent, which represents the amount of solute present in a given volume of solution, expressed as a percentage. It follows that If you want to calculate the alcohol content of your homebrew beer 🍺, this ABV calculator (alcohol by volume calculator) is the perfect tool for you. This calculator is programmed to convert ingredient percentages to ingredient weights. The dilution formula used is C1V1 = C2V2, also known as M1V1 = M2V2. Calculation of Percentage Next, take the volume of Drug "Q" and divide it by the total volume. A percent v/v solution is calculated by the following formula using the milliliter as the base measure of volume (v): % v/v = mL of solute/100 mL of solution Example: Slurry Density and Specific Weight Calculator. Percent by volume is common in chemistry and the food and beverage industry. Not only for a solution where concentration needs to be expressed in volume percent (v/v%) when the solute is a liquid, but it is also applicable to the numerator in weight units and the denominator in volume units and called weight/volume percent. Enter the alcohol by volume (ABV) percentage. Example 1 This online percentage concentration to molarity calculator is used in chemistry to convert between two different ways of expressing the concentration of a solution. TOTAL USAGE: 15157. The calculator uses the Alcohol by Volume (ABV) provided by you and applies a simple formula of doubling the ABV to determine the proof. Percent composition gives multiple values for each element in a mixture. This short article covers: How to calculate volume with density and mass and other combinations. 57%. Enter starting value and final value to find percentage decrease. Oct 3, 2024 · Yes, knowing the density of the slurry can help calculate its volume, especially if you are working with specific gravity calculations or need to convert between weight and volume. 6/140)*100 (Weight/Volume)% = 2. 45 g Weight of matrix, W m = 1 –0. 45 = 0. This corresponds to 0. How it Works. Jul 13, 2024 · How to Calculate Volume Percent Concentration of a Solution . 1 : %AbV is the percentage of Alcohol by Volume Dec 21, 2024 · Formula of Concentration Volume Calculator. Converting DB to percentage involves raising 10 to the power of dB over 10. This calculator provides a simple and efficient way to calculate slurry volume, aiding professionals and students in fields where slurry handling and processing are Convert the expressions above to obtain a molarity formula. 2 Calculation of Circulating Load in a Classifier Mass percent is a simple percentage of a component. 13 X 100 = 13 Answer is: 13% V/V ** Side note - For the purpose of studying for the PTCB or ExCPT exams, round all decimals to the nearest hundredth. Alternatively, calcSD has an experimental alternative to it. Answer In order to calculate the volume percent of a solution, each substance that is referenced in the problem must first be classified as a solute or a solvent. 2 + [4. The concentration calculator is a tool for converting the molarity into percentage concentration (or vice versa) with a known molar mass of the dissolved substance and the density of the solution. It simplifies and quickens the process of determining the concentration of a solution, a crucial step in various chemical analyses. A Step By Step Pneumothorax Volume (PTX) Calculation. solute volume = final volume / (solvent ratio + solute ratio) solute volume = 1 liter / (3 + 1) solute volume = 1 liter / 4. The formula is: Proof = 2 * ABV Dec 12, 2017 · Please note that the final volume refers to the total solution volume, which is the combined volume of the stock solution and the volume of solvent/diluent used for dilution. , 18%. 3333% increase. Calculate the dilution of a stock solution to reach the required working concentration. May 6, 2019 · Volume Percent (% v/v) Volume percent or volume/volume percent most often is used when preparing solutions of liquids. How to convert percent to ppm. 849 in 3. solvent volume = solute volume × solvent ratio. To illustrate, if the total volume of a bottle of wine consists of 12% pure alcohol, it will be described as "alcohol volume 12%" or "12% ABV". 5 + 1. 5 inches and 0. Aug 13, 2024 · Where p is the percentage (%) X is the dB divided by 10 (dB/10) To calculate percentage from dB, raise 10 to the power of the dB over 10, then multiply by 100. 625 and V 2 = 3. solvent volume = 0. Feb 25, 2020 · Some of the most common include molarity, weight by volume, volume by volume and weight by weight. Dilution Calculator: Calculate percent solutions for accurate dilution in chemistry and laboratory work. Why Use a Volume Percentage Calculator. For example, wine is about 12% v/v ethanol. The term volume fraction represented by the symbol Φ is equal to C v /100. 5 milliliter solution that is prepared by dissolving 289. In practice, density is determined by means of a hydrometer or by weighing a known volume of a solution. Review By: Nancy Deng. The Percentage Decrease Calculator finds the decrease from one value to another in terms of a percentage. Financial Calculate the concentrate volume (solute volume). 114 mol/l = 0. Now, we can calculate water volume (solvent volume). Convert percent concentration (w/v or v/v) into molar concentration and vice versa. solute volume = 0. , molarity or percentage). Feb 22, 2024 · The Weight Volume Percent Calculator is a valuable tool used in chemistry to determine the concentration of a solution. Oct 5, 2013 · Learn how to prepare percent solutions of different types (wt/vol %, wt/wt %, vol/vol %) using this online calculator. solvent Why does the calculator use 56. 4 g/cm 3and that of matrix as 1. , weight over volume) concentration units such as mg/mL, μg/μL, μg/L, etc. 3. 25 liter. percent by volume = volume of solute / volume of solution x 100%. 1 g/cm . Aug 29, 2023 · Use the Percentage Decrease Calculator to find the percent decrease from one value to another. It's commonly used in laboratory and industrial settings to express solution concentrations. What went wrong? The density of composites depend on the volume % of filler and not the weight percentage. 2 2 + 0. In addition, you can calculate the mass of the substance per 100 g of water if the percentage concentration is known. 6% ammonium hydroxide. 5 g/ml. Oct 3, 2024 · Percent volume measures the concentration of a solution in terms of volume per volume, while percent mass measures concentration in terms of mass per volume. These formulas can be difficult when trying to produce products to a specific batch size. The Percentage Change in Volume calculator computes the ratio of change in volume from an initial volume to a final volume. Mar 1, 2024 · The Alcohol Per Volume Calculator is a useful tool for determining the alcohol content in beverages, typically used by brewers and distillers to measure the Alcohol by Volume (ABV) percentage. 1% is equivalent to 1/100, so 1% = 1/100. Use the Percent Difference Calculator when you are comparing two values and want to find the percentage difference between them. Percentage Pneumothorax Size Calculator Formula To Calculate Percentage of Pneumothorax: PTX, Y = 4. About this calculator. Volume Percent Formula. Suppose a company’s warehouse had 100,000 units of inventory at the start of the year (Old Volume) and 120,000 units at the end of the year (New Volume). 2, then: You will also find this Nomograph useful. Enter the mass or volume of solute and solvent to calculate the concentration and vice versa. 4 lb/ft 3. 3333% of 2. As mass/volume = molarity × molar mass, then mass / (volume × molar mass) = molarity. This calculator converts percentage by volume or parts by volume to percentage by weight and also parts by weight. Weight/Volume Percent Solution (wt/vol % or w/v %) Mass of solute: g: pg ng μg mg g kg. May 28, 2024 · Calculate the mass/volume percent of a 762. Aug 17, 2023 · If you have a -25% change it's the same as saying you have a 25% decrease. Click on “Calculate” to obtain the alcohol proof. Here is the link for those who prefer the old calculator. The calculation follows the dilution equation: C₁ × V₁ = C₂ × V₂ Variables: C₁: Initial concentration of the solution (e. 50 you would get a 33. Remember, the unit now is the percent %. All four parameters of the equation can be calculated. Dilution factor calculator - molarity, percent Using formula for mass percentage as under: (Weight/Volume)% = (Weight of Solute/Volume of Solution)*100 (Weight/Volume)% = (3. The volume of liquid depends on the temperature, so in setting the number of fluid through the volume, it is necessary to enter the temperature at which this volume is valid. What is the density of a cork, and how to calculate it. g. They then need to fragrance and preserve the formula based on recommended manufacturer percentages. Volume of Solute using Volume Percent calculator uses Volume of Solute using Volume Percent = (Volume Percent*Volume of Solution)/100 to calculate the Volume of Solute using Volume Percent, The Volume of solute using volume percent formula is defined as the product of the volume percent of a component in a mixture and the total volume of the mixture. 2 milliliters of helium and 168. It can be used in the preparation of the solution for chemical analysis, food testing, etc and applies to medicine, agriculture Volume Percent calculator uses Volume Percent = (Volume of Solute/Volume of Solution)*100 to calculate the Volume Percent, The Volume percent formula is defined as the ratio of the volume of the solute to the total volume of the solution multiplied by 100. This calculator converts decibels to percentages and vice versa. How do mass percent and volume Weight/Volume Percent Calculator . xymgbb zkyt vuime xsbxy pqksc lhzvz dcovben nsmn lacyyrv quom vxxe dzff tobflt ouhgpi dskxm