Molarity Calculator
Find the molarity of a solution, or rearrange the formula to solve for moles or volume. You can also enter a mass and molar mass to work out the number of moles first.
How to calculate molarity
- Enter any two of moles, volume in litres and molarity.
- Or enter mass and molar mass to derive the moles automatically.
- Read off the missing quantity, computed from M = moles / volume.
Examples
From moles and volume
0.5 mol in 2 L
0.25 M
From mass and molar mass
58.44 g NaCl (MM 58.44) in 1 L
1 M
Frequently asked questions
What is molarity?
Molarity is the concentration of a solution measured in moles of solute per litre of solution, written mol/L or M.
What is the molarity formula?
Molarity equals moles of solute divided by volume of solution in litres, M = n / V. Rearranged, n = M times V and V = n / M.
How do I find moles from a mass?
Divide the mass in grams by the molar mass in grams per mole. This tool does that for you when you enter both values.
Do I use the volume of solution or solvent?
Use the total volume of the final solution, not the volume of solvent added, because the solute also takes up space.
How do I convert millilitres to litres?
Divide millilitres by 1000. For example 250 mL is 0.25 L. Enter the litre value into the volume field.
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