Calculators
Dilution Calculator
Solve the dilution equation C1 x V1 = C2 x V2 for a missing concentration or volume with common units, locally in your browser.
Use the dilution equation C1 x V1 = C2 x V2 to find a missing concentration or volume. Enter the stock and final values, then choose which one to solve for. Calculations run locally in your browser; your values are not uploaded or stored.
This is the value being calculated.
Solve C1 x V1 = C2 x V2 for any missing value.
Dilution keeps the amount of solute constant, so the stock concentration times the stock volume equals the final concentration times the final volume. Enter any three of the four values and solve for the fourth: stock concentration (C1), stock volume (V1), final concentration (C2), or final volume (V2). Concentrations can be entered in molar units (nM, µM, mM, M), mass-per-volume units (µg/mL, mg/mL, g/L), percent w/v, or fold dilution, as long as the stock and final concentrations use the same unit family. Volumes can be entered in µL, mL, or L independently. The result reports all four values, the dilution factor, and the volume of diluent to add when the final volume is larger than the stock volume. For example, diluting 1 mL of a 1 M stock to 100 mL gives a 10 mM final concentration, a 100x dilution factor, and 99 mL of diluent. This assumes ideal mixing and that the stated volumes are the finished volumes. All calculations run locally in your browser; your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
How does the dilution calculator work?
It uses the dilution equation C1 x V1 = C2 x V2, where C1 and V1 are the stock concentration and volume and C2 and V2 are the final concentration and volume. Enter any three values and choose which one to solve for. For example, 1 mL of a 1 M stock diluted to 100 mL gives C2 = C1 x V1 / V2 = 1 x 1 / 100 = 0.01 M, or 10 mM, a 100x dilution.
What do C1, V1, C2, and V2 mean?
C1 is the concentration of the stock or starting solution and V1 is the volume of that stock you measure out. C2 is the desired final concentration and V2 is the final total volume of the diluted solution. The calculator labels each field so you can see which value it is solving for.
Which concentration and volume units can I use?
Concentrations can be entered in molar units (nM, µM, mM, M), mass-per-volume units (µg/mL, mg/mL, g/L), percent w/v, or as a fold dilution (x). The stock and final concentration must use the same unit family, for example both molar, because molarity and mass concentration are not interchangeable without the solute molar mass. Volumes can be entered in microlitres (µL), millilitres (mL), or litres (L), and the stock and final volumes may use different units.
What is the dilution factor and how much diluent do I add?
The dilution factor is the stock concentration divided by the final concentration, C1 / C2, which also equals V2 / V1. A 1:100 dilution has a factor of 100. When the final volume is larger than the stock volume, the extra volume is the diluent (usually water or buffer) to add, calculated as V2 - V1. For 1 mL of stock made up to 100 mL, add 99 mL of diluent.
Does this calculator account for mixing or temperature?
No. It assumes ideal mixing, that the stated volumes are the finished volumes, and that the concentration is expressed per final volume. Concentrations in molarity can shift slightly with temperature, and some solutions change volume when mixed, so verify critical laboratory work with calibrated glassware and standard procedure. This is an educational estimate, not a substitute for laboratory guidance, and all calculations run locally in your browser.