Calculate the density of a solution from its mass and final volume, or find mass or volume from density, with optional mass percent and molarity.

Use the volume after mixing; component volumes may not add up.

Composition analysis

Solution Density Formula

The following formula is used to calculate the density of a solution:

D = MS / V
  • D is total solution density; g/cm³ and g/mL are equivalent units.
  • MS is the mass of the solution (g)
  • V is the final mixed-solution volume (mL or cm³ for the displayed formula), not the sum of component volumes.

Choose density (D = MS/V), mass (MS = D × V), or final solution volume (V = MS/D), then choose the visible result unit. Enter total solution mass, not only solute mass. Optional composition analysis uses solute mass from zero up to total solution mass: mass fraction = solute mass/total mass × 100%, and mass concentration = solute grams/final solution liters in g/L. An optional positive molar mass in g/mol also gives amount concentration, commonly called molarity: (solute grams/molar mass)/final liters in mol/L; blank omits it. Composition describes the entered solution and does not predict density. Your last successful inputs are saved in this browser; other scripts on this site may access them, and Reset clears this calculator’s saved data.

Solution Density Definition

What is a solution density?

A solution contains more than one substance in a liquid or solid phase, with solvent and solute roles distinguished; it is not limited to combining liquids. Solution density is the total mass divided by the final solution volume. See the IUPAC definitions of solution and density. Use mass, density and volume for the same composition, temperature and pressure. Mixing can change volume, so component volumes must not simply be added. The calculator does not model contraction, thermal expansion or chemical reactions.

Example Problem

How to calculate a solution density?

This example illustrates the density arithmetic. For a measured value, use suitable mass and final-volume measurements, subtract the empty container mass, and report the measurement temperature and pressure; ordinary beaker markings do not establish high precision.

First, measure the empty beaker mass. For this example, it is 15 grams.

Next, add the solution and measure the combined mass: 100 grams. The solution mass is 100 − 15 = 85 grams.

The final solution volume in this arithmetic example is 25 mL.

Finally, calculate the solution density using the formula above:

D = (MB+S – MB) / V

D = (100 – 15) / 25

D = 3.4 g/mL = 3.4 g/cm³ = 3400 kg/m³.