Serial Dilution Calculator

About this calculator

In a serial dilution, each step dilutes the previous solution by the same fold factor D (for example, transferring 1 part sample into 9 parts diluent gives D=10), so after n steps the final concentration is C₀/Dⁿ and the total dilution factor is Dⁿ — a 1:10 dilution repeated 6 times gives a million-fold total dilution.

Microbiologists use serial dilution to bring a bacterial culture down to a countable number of colonies on a plate (typically 30-300 CFU), pharmacologists prepare dose-response curves by serially diluting a drug across a plate, and immunologists titrate antibodies the same way to find the concentration that still gives a usable signal — the math matters because a single dilution error compounds through every later step.