Molarity Calculator
Calculate molarity (mol/L) from moles and volume, or from mass and molar mass. Essential for chemistry lab work. Also outputs mg/mL concentration.
How to use this tool
- Enter moles of solute (n), volume of solution, mass of solute (optional) and molar mass of solute (optional) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your molarity and the full breakdown beneath it.
Molarity (M) = moles of solute / litres of solution. If you know the mass and molar mass instead, calculate moles first: n = mass / M_r, then M = n / V.
Frequently asked questions
- What is the difference between molarity and molality?
- Molarity (M) is moles per litre of solution; molality (m) is moles per kilogram of solvent. Molality doesn't change with temperature; molarity can because liquids expand.
- How do I make a 1 M NaCl solution?
- Dissolve 58.44 g of NaCl (molar mass ≈ 58.44 g/mol) in enough water to make exactly 1 litre of solution.