Question 1

Which dilution calculator should I use?

Accepted Answer

Use the dilution calculator when you know concentrations and volumes (C₁V₁ = C₂V₂). Use the dilution factor calculator when a protocol speaks in fold-changes ("dilute 25×"), the dilution ratio calculator when it speaks in parts ("mix 1:10"), the serial dilution calculator for a series of steps, and the alcohol dilution calculator for spirits and ethanol strengths.

Question 2

Are the tools free?

Accepted Answer

Yes. Every calculator and table on the site is free to use, needs no account and runs entirely in your browser — nothing you type is sent to a server.

Question 3

How accurate are the results?

Accepted Answer

Each tool applies the textbook formula exactly, prints it next to the result and is covered by automated tests against worked examples. The method section of every page lists the assumptions and sources, and the date the formulas were last reviewed.

Question 4

Which units can I use?

Accepted Answer

The calculators accept the usual lab units — molar (M to nM), mass per volume (g/L, mg/mL, µg/mL, …), percent, and volumes from liters to femtoliters — and convert within a family automatically. Converting across families, say percent to molarity, needs the substance’s molar mass; the protein molarity calculator does exactly that for proteins.

Question 5

Can I suggest a tool?

Accepted Answer

Please do. Write to the address in the footer with the calculation you keep doing by hand and, if you have one, the formula or source you use; the most requested tools are added first.

Lab calculators that do the arithmetic for you

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Dilution

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Reference

Frequently asked questions