Dilution calculator, C1V1 = C2V2

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

C₁

· concentration of the initial solution (before dilution).

V₁

· volume of initial solution taken.

C₂

· concentration of the final solution (after dilution).

V₂

· final volume of the diluted solution.

This tool assumes you're starting from a liquid stock solution: it only works by adding solvent, never by dissolving a solid. If you're starting from a mass of solid product (powder, crystals) to weigh out. Use Solution preparation (m = C × V × M) instead, which computes the mass to weigh for a target concentration. The two tools are complementary: prepare a concentrated stock solution by weighing, then dilute it with this one.

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 knowing the molar mass of the solute: C₁ and C₂ must therefore stay within the same unit group.

A dilution always adds solvent: the volume can only increase, and the concentration can only decrease (or stay equal). If the entered values would imply the opposite (a volume that decreases or a concentration that increases) the tool explicitly refuses the result rather than showing a mathematically correct but physically absurd number for a dilution: that case corresponds to concentrating (evaporation, adding solute). Not diluting.

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).