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Solutions · Concentration

Molarity, Normality & Mass Percent Converter

Convert molarity, normality, mass percentage, and mass concentration using molar mass, solution density, and a defined equivalence factor.

Formula shown Runs locally Reviewed Aug 11, 2026
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Equation guide

Conversions for one solute in a solution of known density and reaction context

Normal concentration

N = zMz: equivalents per mole

Mass concentration

β = M Mₘβ in g/L

Mass percentage

w% = β/(10ρ)ρ in g/mL
Solution concentration

Convert concentration with chemical context

Use the density of the solution at its measured concentration and temperature—not the density of pure solvent. Inputs and displayed results use at most three decimal places.

N = zM

Enter one concentration plus the molar mass, equivalence factor, and solution density.

Using the model

Symbols, assumptions and limitations

Interpretation notes

M is molarity, N is normality, z is the reaction-dependent equivalence factor, β is mass concentration in g/L, Mₘ is molar mass in g/mol, and ρ is solution density in g/mL. The entered density and concentration must imply a mass percentage from 0% through 100%. Normality is meaningful only for a specified reaction.

Worked examples

See the method in practice

01

Sulfuric acid in acid–base work

For H₂SO₄ with z = 2, a 1 mol/L solution is 2 eq/L. Its mass percentage additionally depends on solution density.

02

Sodium hydroxide solution

For NaOH with z = 1, molarity and normality have the same numerical value, while mass percent is obtained from molar mass and density.

Questions

Frequently asked

Why is density required for mass percent?

Molarity refers to solution volume, while mass percent compares solute mass with total solution mass. Density connects those two bases.

What is the equivalence factor z?

It is the number of reactive equivalents per mole for the stated reaction—for example, transferable H⁺ in an acid–base reaction. It can change with reaction context.

Is normality an intrinsic property of a solution?

No. Unlike molarity, normality depends on the reaction being considered, so the equivalence factor must always be stated.

Sources & review

Equations and examples are checked against the references below. Results are educational and should be independently verified for safety-critical work.

OpenStax Chemistry — Molarity

Written by the STEM Hub editorial team · Reviewed August 11, 2026 · Review methodology