Molarity Calculator

Calculate molarity, moles, volume, mass, or perform dilution calculations with M1V1=M2V2. Free, fast, and easy to use.

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Choose a calculation type, enter your values, and click Calculate Now to get instant results with step-by-step solutions.

Complete User Guide

What is Molarity?

Molarity (M) is a measure of solution concentration defined as the number of moles of solute per liter of solution. It is the most common unit for expressing concentration in chemistry. A 1 M solution contains exactly 1 mole of solute dissolved in enough solvent to make 1 liter of total solution.

All Formulas at a Glance

Molarity: M = n / V

Moles: n = M × V

Volume: V = n / M

Moles from Mass: n = mass / MW

Dilution: M1 × V1 = M2 × V2

6 Calculation Types

Molarity from Moles & Volume

M = n / V. Enter moles and volume to find concentration.

Moles from Molarity & Volume

n = M × V. Find how many moles are in a solution.

Volume from Molarity & Moles

V = n / M. Find the volume needed for a given number of moles.

Molarity from Mass & MW

Enter mass, molecular weight, and volume to find molarity.

Mass from Molarity & MW

Find how many grams of solute to weigh for a target concentration.

Dilution (M1V1 = M2V2)

Find the final volume or final molarity after diluting a stock solution.

Supported Units

Volume

  • L — Liters
  • mL — Milliliters
  • µL — Microliters
  • cm³ — Cubic Centimeters
  • m³ — Cubic Meters

Mass

  • g — Grams
  • mg — Milligrams
  • µg — Micrograms
  • kg — Kilograms

Quick Examples

• 0.5 mol in 1 L → 0.5 M

• 58.44 g NaCl (MW 58.44) in 1 L → 1 M NaCl

• Dilute 100 mL of 2 M to 0.5 M → V2 = 400 mL (add 300 mL water)

• 1 M × 0.25 L = 0.25 mol

Important Notes

  • Molarity uses volume of solution, not volume of solvent.
  • In dilutions, M2 must be ≤ M1 (you cannot concentrate by adding solvent).
  • All volumes are internally converted to liters for calculations.
  • Molecular weight (MW) must be in g/mol.

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