Molarity Calculator
Calculate the molarity, mass, volume, or moles of a chemical solution step-by-step. Find molar mass and concentration instantly with our free chemistry solver.
Solution Concentration Solver
Enter known values to find the missing property
Select the property you want to find
Enter the mass in grams
Enter the molar mass (e.g., NaCl = 58.44)
Enter the total volume in liters
Solution Properties
Concentration, moles, mass, and volume breakdown
Select what you want to calculate, enter your known values, and click Calculate to see the step-by-step solution.
Essential Chemistry Formulas
Common mathematical formulas used to calculate solution concentration and properties.
| Formula Name | Equation / Expression | Description |
|---|---|---|
| Molarity | M = n / V | Moles of solute divided by liters of solution |
| Moles | n = m / M_w | Mass divided by molar mass |
| Mass | m = n × M_w | Moles multiplied by molar mass |
| Dilution | M1V1 = M2V2 | Initial molarity and volume equals final molarity and volume |
| Molality | m = n / kg_solvent | Moles of solute divided by kilograms of solvent |
Molarity Calculator FAQ
Everything you need to know about calculating solution concentration and molarity.
Molarity (M) is a measure of the concentration of a solute in a solution. It is defined as the number of moles of solute divided by the total volume of the solution in liters (L). It is one of the most common units used in chemistry to express concentration.
To calculate molarity, you use the formula M = n / V, where ‘n’ is the moles of solute and ‘V’ is the volume of the solution in liters. If you only have the mass of the solute, you first convert it to moles using the molar mass (n = mass / molar mass), and then divide by the volume.
Molarity (M) is the number of moles of solute per liter of solution. Molality (m) is the number of moles of solute per kilogram of solvent. Molarity changes with temperature because the volume of a liquid expands or contracts, whereas molality remains constant because mass does not change with temperature.
The molar mass of a compound is calculated by adding up the atomic weights of all the atoms in its chemical formula. For example, the molar mass of NaCl (table salt) is the atomic weight of Sodium (22.99 g/mol) plus the atomic weight of Chlorine (35.45 g/mol), which equals 58.44 g/mol.
The standard unit of molarity is moles per liter (mol/L), which is often abbreviated with a capital M (e.g., a 1 M solution means 1 mole per liter). Other common units include millimolar (mM) or micromolar (μM) for very dilute solutions.
The dilution formula M1V1 = M2V2 is used when you are adding solvent to a solution to lower its concentration. ‘M1’ and ‘V1’ are the initial molarity and volume, while ‘M2’ and ‘V2’ are the final molarity and volume. If you know any three of these values, you can easily solve for the fourth.