Dilution calculator, C1V1 = C2V2

Three values among the initial concentration (C1), initial volume (V1), final concentration (C2) and final volume (V2) give the fourth, from C1 × V1 = C2 × V2.

The amount of solute stays constant during a dilution: only the concentration changes as the volume changes.

C₁

concentration of the initial solution.

V₁

volume of initial solution taken.

C₂

concentration of the final solution.

V₂

final volume of the diluted solution.

This tool starts from a liquid stock solution and models only the addition of solvent. For a mass of solid to weigh out, the matching tool is Solution preparation (m = C × V × M).

Molar concentrations (mol/L, mmol/L, µmol/L) and mass concentrations (g/L, mg/mL, mg/L, µg/mL) cannot be converted into each other without the molar mass of the solute; C₁ and C₂ stay within the same unit group.

A dilution adds solvent: the volume increases and the concentration decreases, or stays equal in the limiting case. Values implying the opposite are refused; they describe a concentration (evaporation, adding solute).

To prepare 100 mL of a 0.1 mol/L solution from a 1 mol/L stock solution, take 10 mL of stock solution (1 mol/L × 10 mL = 0.1 mol/L × 100 mL).