Dilution Calculator (C1V1 = C2V2): calculate percent dilution, dilution factor, stock volume (V1), final volume (V2), and solvent volume for solution preparation.
Use this percent solution dilution calculator to work out stock concentration, target concentration, stock volume (V1), final volume (V2), or the solvent volume to add when preparing diluted solutions. It is useful in chemistry, laboratory work, cleaning solutions, and any task where you need a specific lower percentage concentration.
How to calculate a dilution in 3 steps:
- Enter the stock (starting) concentration and the target (final) concentration.
- Enter either the stock volume (V1) or the final volume (V2) — whichever you already know.
- Read the missing value and the solvent volume to add instantly, using C1V1 = C2V2.
Example: dilute a 30% stock solution down to 5% in a final volume of 1.5 L. Using C1V1 = C2V2: 30 × V1 = 5 × 1.5, so V1 = 0.25 L of stock, plus 1.25 L of solvent added.
The C1V1 = C2V2 formula is unit-independent — it works the same way whether concentration is in percent (%), molarity (mol/L or mM), or mass/volume (mg/mL), which makes it equally useful for diluting antibody stocks, reagents, and other lab solutions to a target concentration, not only percent solutions.
The calculator applies the C1V1 = C2V2 dilution relationship, lets you switch common volume units, and supports reverse calculation when one concentration or volume is missing. It also shows the added solvent volume so you can prepare the final mixture directly.
Dilution formulas
$$C_{1}V_{1} = C_{2}V_{2}$$ $$V = V_{2} - V_{1}$$
Frequently asked questions about percent solution dilution
This calculator uses the standard dilution formula C1V1 = C2V2, where C1 and V1 are the stock concentration and stock volume, while C2 and V2 are the target concentration and final volume.
Enter the starting concentration C1, the target concentration C2, and the final volume V2. The calculator then solves for the required stock volume V1 automatically.
After the stock volume is known, the added solvent volume is calculated as V = V2 - V1. This tells you how much water or other solvent must be added to reach the final solution volume.
The dilution factor describes how many times the original solution is diluted, while the percent dilution expresses the reduction in concentration as a percentage. Both are useful for understanding how much weaker the final solution is compared with the stock solution.
Yes. If one of the four main values in C1V1 = C2V2 is unknown, this calculator can solve for it. You can also switch volume units as needed, as long as the solution volumes are compared consistently.
Yes. The C1V1 = C2V2 relationship is the same regardless of concentration unit. Enter your molarity (mol/L, mM, µM) or mass/volume (mg/mL) values in the concentration fields the same way you would percent values — the calculated stock volume, final volume, and solvent volume are correct as long as C1 and C2 use the same unit.
Yes. Enter the stock concentration (C1), the stock volume (V1) if known, the target concentration (C2), and the final volume (V2) if known. The calculator solves for whichever value is missing, which works the same way for reagent, antibody, buffer, and other lab stock dilutions as it does for percent solutions.
