Serial Dilution Calculator

Get the concentration at every step of your dilution series — plus exactly how much sample and diluent to add per tube.

TubeTotal dilutionConcentration

How to make a serial dilution

A serial dilution is a stepwise dilution where each tube is diluted from the one before it by the same factor, letting you span many orders of magnitude with small, accurate steps. For a 10-fold series you move 1 part sample into 9 parts diluent at each step. The concentration in tube n is the stock divided by the dilution factor raised to the n — so a 10-fold series starting at 1,000,000 gives 100,000 then 10,000 then 1,000, and so on. To prepare each tube, add the transfer volume of sample to the diluent volume: for a chosen final volume V and factor F, transfer V/F of sample into V − V/F of diluent, mixing well before moving to the next tube.

Concentration units carry through unchanged — use cells/mL, M, µg/mL, whatever your stock is in.

Related tools: Single dilution (C₁V₁) · all biochem tools.