Mass Concentration Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/9/2026
Mass concentration is calculated with solute mass (g) ÷ solution volume (L). Dissolving 10 g of solute in 0.5 L of solution gives a mass concentration of 20 g/L.
Explanation
Mass concentration expresses the amount of solute dissolved per liter of solution, in grams — a unit directly usable with a scale and a graduated cylinder, without needing to know the compound's molar mass. This is what distinguishes it from molar concentration (in mol/L), which expresses the same idea but as a number of moles rather than a mass: the two quantities are related through the solute's molar mass (mass concentration = molar concentration × molar mass), and convert easily from one to the other with the moles calculator. Mass concentration is the most intuitive unit for a lab or kitchen preparation (for example, a saline solution at a certain number of grams per liter), while molar concentration remains essential as soon as reasoning about the proportions of a chemical reaction, where it's the number of molecules that matters, not their mass.
Example: 10 g of solute in 0.5 L of solution
Inputs
Solute mass: 10 g. Solution volume: 0.5 L.
Calculation
Mass concentration = 10 ÷ 0.5 = 20 g/L.
Result
This solution has a mass concentration of 20 g/L.
Frequently asked questions
How do you convert mass concentration to molar concentration?
By dividing the mass concentration (g/L) by the solute's molar mass (g/mol): molar concentration = mass concentration ÷ molar mass. For example, 5.844 g/L of sodium chloride (molar mass 58.44 g/mol) equals 0.1 mol/L — use the moles calculator for this conversion from a given mass and volume.
Is the volume used that of the solvent or of the final solution?
It's the total volume of the final solution (solute + solvent combined), not just the volume of solvent added initially. This is an important distinction: dissolving a solute in a volume of solvent doesn't always give exactly the same final solution volume, depending on the mixture's properties.
Why do some labels show concentration as a percentage rather than in g/L?
A mass percentage (g of solute per 100 g of solution) or volume percentage is another common way to express a concentration, practical especially for household or food products. Converting between these units requires knowing the solution's density, an additional parameter not needed for mass concentration in g/L.