🧪 Dilution Calculator (C1V1=C2V2)
Solve the dilution equation C₁V₁ = C₂V₂ for any missing value, plan a serial dilution tube-by-tube, or compute a dilution factor.
Enter any three — leave the one you want to solve for blank.
C₁V₁ = C₂V₂ · use the same unit for both concentrations and both volumes
How the dilution calculator (c1v1=c2v2) works
The dilution equation C₁V₁ = C₂V₂ (equivalently M₁V₁ = M₂V₂) relates the concentration and volume of your stock to the concentration and volume of your final solution. Enter any three values and the fourth is solved. The serial-dilution planner gives the transfer and diluent volume for each tube and the cumulative dilution factor. Units are yours to choose — as long as concentrations share a unit and volumes share a unit, the answer is consistent.
Because you supply the units (M, mg/mL, µg/mL, % w/v), there is nothing to maintain and no lookup table to go stale — the maths is exact for whatever units you use consistently.
Frequently asked questions
What is the C1V1 = C2V2 formula?
It is the dilution equation: the amount of solute is conserved, so stock concentration × stock volume = final concentration × final volume. Rearranged, the volume of stock you need is V₁ = C₂V₂ / C₁.
How do I make a specific dilution?
Enter your stock concentration (C₁), the concentration you want (C₂) and the final volume (V₂); the tool gives V₁, the volume of stock to use. Top up with diluent to V₂. For example, to make 100 mL of 1× from a 10× stock: V₁ = (1 × 100)/10 = 10 mL stock + 90 mL diluent.
What is a serial dilution?
A stepwise dilution where each tube is diluted by the same factor from the previous one, giving an exponential concentration series (e.g. 1:10, 1:100, 1:1000). The planner here lists the transfer volume and diluent for each tube and the cumulative fold-dilution.
What is a dilution factor?
The ratio of final volume to sample volume — how many times more dilute the result is. A dilution factor of 10 means the sample is 10× more dilute (a 1:10 dilution).
Do the units matter?
Only that they are consistent: use the same unit for both concentrations and the same unit for both volumes. The tool is unit-agnostic, so it works for molarity, mg/mL, %, or any other concentration unit.
Is this the same as M1V1 = M2V2?
Yes — M₁V₁ = M₂V₂ is the same equation written with molarity as the concentration. C₁V₁ = C₂V₂ is the general form for any concentration unit.