๐ŸงชSerial Dilution Calculator

Plan a dilution series, solve for the required factor, or back-calculate CFU/mL from plated colonies.

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Free Serial Dilution Calculator

Setting up a dilution series for lab work? Our free serial dilution calculator does the math for you. Enter your starting concentration, dilution factor, and number of steps, and get a full table showing exactly how much stock and diluent to use at every tube โ€” plus the resulting concentration after each step.

Need equal log-steps to hit a specific target concentration? Switch to solve-for-factor mode and the calculator works out the right dilution factor automatically. Microbiology users get a dedicated CFU/mL mode: enter your plated colony count, dilution factor, and volume plated, and back-calculate the original bacterial concentration instantly.

A simple visual diagram shows the full dilution chain so you can double-check your setup before you're at the bench. No sign-up, no downloads โ€” just accurate dilution math whenever you need it. See the About page or the FAQ for more.