Dilution Calculator

The Dilution Calculator solves the dilution equation for whichever quantity you're missing: stock concentration, stock volume, final concentration, or final volume.

The dilution equation

Diluting a stock solution doesn't change the amount of solute — only how much solvent it's spread across. That conservation gives the standard relationship:

C₁V₁ = C₂V₂

where C₁/V₁ are the stock's concentration and volume, and C₂/V₂ are the final (diluted) concentration and volume. Given any three, the fourth is fixed.

How to use it

1. Pick what you want to Solve for — stock concentration, stock volume, final concentration, or final volume.
2. Fill in the other three values, each with its own unit — concentrations in M, mM, µM, or nM; volumes in µL, mL, or L.

Every value is converted to a common base (mol/L and L) before solving, so a 10 M stock can be diluted into a 1 mM target without doing any unit conversion by hand — the calculator handles mismatched units across the four fields automatically.

The result includes the solved value, a full breakdown of all four quantities, the dilution factor (C₁ ÷ C₂), and how much diluent (solvent) to add — the number you actually need at the bench, since V₂ − V₁ is the volume of water (or buffer) to add to your stock aliquot to reach the final volume.

Example

To make 100 mL of a 1 M solution from a 10 M stock:

V₁ = (C₂ × V₂) ÷ C₁ = (1 M × 100 mL) ÷ 10 M = 10 mL

Measure out 10 mL of the 10 M stock, then add 90 mL of solvent to reach 100 mL total — a 10× dilution.

Does this work for serial dilutions?

Not directly — this calculator solves one dilution step at a time. For a serial dilution (repeated fixed-ratio dilutions), run it once per step, using each step's output volume as the next step's stock volume.

What if my stock and target use different concentration units?

That's exactly what the per-field unit selectors are for — enter C₁ in M and C₂ in mM (or any other combination) and the calculator converts both to a common base before solving, then reports the answer back in whichever unit you selected for that field.

Privacy

All calculations run entirely in your browser. Your figures are never uploaded or stored.