Dilution Calculator
Calculate stock solution volume, diluent volume and dilution factor using C1V1 = C2V2.
Calculate solution dilution with C1V1 = C2V2
Find stock volume and diluent volume for a target concentration and final volume.
How the Dilution Calculator works
The standard dilution relationship is C1V1 = C2V2, where C1 is stock concentration, V1 is stock volume, C2 is desired concentration and V2 is desired final volume. Sigma-Aldrich and Thermo Fisher publish the same relationship in their laboratory dilution guidance. Solving for V1 gives the stock aliquot required.
How to use this dilution calculator
Enter stock and desired concentrations in the same units—for example both mM or both ng/µL—and enter final volume in millilitres. The tool calculates stock volume and the remaining volume to be made up with diluent. If you prefer µL, multiply the returned millilitres by 1,000.
How to interpret the result
Dilution factor is stock concentration ÷ final concentration. A 10× dilution means the final solution is one-tenth the stock concentration and one-tenth of the final volume comes from stock under this simple model. The stock-fraction output provides the same relationship as a percentage.
Assumptions and limitations
This equation assumes the analyte amount is conserved and concentration units are directly compatible. Highly concentrated acids/bases, solutions defined by mass fraction/density, non-additive volumes or chemical reactions may require additional information. Laboratory safety, mixing order and compatibility are outside the calculation.
Practical example and workflow
To make 50 mL of 10 mM solution from a 100 mM stock, V1 = 10×50/100 = 5 mL of stock and 45 mL diluent. A technician can scale the final volume while keeping the concentration ratio unchanged.