Solution Mixing Calculator
Calculate the resulting concentration and volume when two solutions of differing strength are combined.
mol/L
L
mol/L
L
Weighted average concentration of the blend
- 1
Moles from solution 1
1 × 100 = 100 mol - 2
Moles from solution 2
0.5 × 200 = 100 mol - 3
Total moles
100 + 100 = 200 mol - 4
Final volume
100 + 200 = 300 L - 5
Final concentration Cf
200 ÷ 300 = 0.6667Volume-weighted average of the two starting concentrations.
How does this calculator work?
Mixing two solutions gives a final concentration equal to the volume-weighted average of the two: Cf = (C1·V1 + C2·V2) / (V1 + V2). The final volume is the sum V1 + V2, assuming volumes add. Set one concentration to zero to model dilution with pure solvent.
Formula
How this is calculated
Enter the concentration and volume of each solution. C1 and C2 are the molar concentrations (or any consistent concentration unit) of solutions 1 and 2, while V1 and V2 are their respective volumes.
The amount of solute contributed by each solution equals concentration times volume (C·V). Adding the two amounts gives the total solute (C1·V1 + C2·V2). Assuming the volumes are additive, the final volume is simply Vf = V1 + V2, and the final concentration is the total solute divided by the final volume: Cf = (C1·V1 + C2·V2) / (V1 + V2). The result is a volume-weighted average of the two starting concentrations.
Use consistent units: if concentrations are in mol/L and volumes in L, the total amount is in moles and Cf is in mol/L. The additive-volume assumption is accurate for dilute aqueous solutions but can deviate slightly for concentrated mixtures where excess volumes of mixing occur. The calculation is undefined when the combined volume is zero.
Frequently asked questions
Use any consistent set, for example mol/L for concentration and L for volume. The final concentration comes out in the same unit you entered for the inputs.
Yes. It assumes ideal additive mixing, so Vf = V1 + V2. This holds well for dilute solutions but may be slightly off for concentrated mixtures.
Yes. Set the second concentration C2 to 0 and V2 to the volume of water added to find the diluted concentration.
Also known as
TG we-Calculate Editorial Team. (2026). Solution Mixing Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/solution-mixing-calculator
TG we-Calculate Editorial Team. "Solution Mixing Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/solution-mixing-calculator.
TG we-Calculate Editorial Team, "Solution Mixing Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/solution-mixing-calculator
@misc{wecalculate_solution_mixing_calculator, title = {Solution Mixing Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/solution-mixing-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?