Serial Dilution Calculator

About this calculator

Serial dilution repeatedly dilutes a solution by the same factor at each step (e.g. 1:10) so the total dilution after n steps is the per-step factor raised to the nth power, and the final concentration equals the starting concentration divided by that total dilution factor. Doubling or halving errors compound quickly, which is exactly why the geometric progression matters.

Microbiologists rely on serial dilution to bring bacterial or viral samples into a countable range for colony-forming unit (CFU) plating; pharmacologists use it to prepare a range of drug concentrations for dose-response curves; and analytical chemists use it to build calibration standards for assays like ELISA. Enter the starting concentration, the dilution factor per step, and the number of steps to find the final concentration.