Solution Concentration Converter

Convert solution concentration between mass percent, ppm by mass, mg/L, g/L, and kg/m³ using an explicit solution density.

Convert instantly

Enter a value and choose the units. Your answer updates as you type.

Value

Solution density (kg/L)

Default 1 kg/L is a water-like assumption. Use the measured solution density for a defensible mass/volume conversion.

From

Result

10000 Parts per million by mass (ppmw)

Mass percent and ppmw are mass-based. mg/L and g/L are volume-based and require solution density; the default density is 1 kg/L only as an explicit water-like assumption, not a universal equivalence.

Quick reference

Percent by mass (% w/w)100 × mass fraction
Parts per million by mass (ppmw)1,000,000 × mass fraction
Milligram per liter (mg/L)density-dependent
Gram per liter (g/L)density-dependent
Kilogram per cubic meter (kg/m³)density-dependent

About the Solution Concentration Converter

Solution concentration has two different bases: % w/w and ppmw divide solute mass by total solution mass, while mg/L, g/L, and kg/m³ divide solute mass by solution volume. Density is therefore required when moving between mass-based and volume-based reporting; there is no universal ppm-to-mg/L identity.

For example, at a solution density of 1.2 kg/L, 100 ppmw corresponds to 120 mg/L (0.12 g/L); at the water-like default density of 1 kg/L it corresponds to 100 mg/L. Enter the measured density before comparing a Molar Concentration Converter result with the Density Converter.

Frequently asked questions

Is ppm always equal to mg/L?

No. ppmw is mass per mass, while mg/L is mass per volume. They are numerically equal only under the explicit 1 kg/L density assumption.

How does density change the result?

At 1.2 kg/L, 100 ppmw equals 120 mg/L; increasing solution density increases the mass-per-volume value for the same mass fraction.

What density should I enter?

Use the measured density of the solution at the relevant temperature. The default 1 kg/L is only a water-like assumption for quick estimates.

Take this calculation further

Browse the converters calculators collection for more tools in this subject.

For a related calculation, use Density Converter to convert density accurately between kilograms per cubic meter, grams per cubic centimeter, kilograms per liter, pounds per cubic foot, and more. Alternatively, use Molar Concentration Converter to convert molar concentration between mol/L, mol/m³, mmol/L, kmol/m³, and other chemically useful units.

For the underlying method, read Viscosity Explained: Dynamic vs. Kinematic and Why It Matters.