labmatetools / 2.2 DILUTION ALL TOOLS

Dilution Calculator

Fill in three of the four values in C₁V₁ = C₂V₂. You get the missing one, how much stock and diluent to pipette, and the dilution factor.

SECTION 02 — CALCULATORS · 2.2ENTER → SOLVE → PIPETTE

SOLVE FOR
C1STOCK CONC.
V1STOCK TO ADD
C2FINAL CONC.
V2FINAL VOLUME
ANSWER

RECIPE
  1. STOCK—
  2. DILUENT—
  3. MAKES—
ABOUT THIS TOOL

How to use

  1. Pick what you want to find under SOLVE FOR. Most of the time that is V1: how much stock to add.
  2. Type the other three values and pick their units. Units can differ — mM stock into µM final, mL into µL — the tool converts.
  3. Both concentrations must be the same kind: molar with molar, mass with mass, % with %, X with X. To go between molar and mg/mL, use the Molarity tool.
  4. The recipe shows how much stock and how much diluent (water, buffer or medium) to mix.
  5. If the stock volume is under 1 µL, you get a two-step plan with an intermediate dilution so you can pipette it accurately.
  6. COPY RECIPE puts the result on your clipboard, ready to paste into your notebook.

The formula

C1 × V1 = C2 × V2
C1concentration of the stock
V1volume of stock to take
C2concentration you want
V2total volume you want to end up with

Diluent to add = V2 − V1. Dilution factor = C1 ÷ C2.

Example. 1 mL of 10 µM from a 1 mM stock: V1 = 10 µM × 1 mL ÷ 1 mM = 10 µL. Add 10 µL stock to 990 µL diluent — a 1:100 dilution.

Good to know

  1. Free to use. No subscription. Nothing you type leaves your browser.
  2. “1:100” here means 1 part stock in 100 parts total (1 + 99), the usual lab reading.
  3. Results are rounded to 4 significant figures.
  4. A calculator, not a protocol: check the numbers against your own method.
QUESTIONS · DILUTION CALCULATOR

Frequently asked

How do I calculate how much stock to add?

Use V₁ = C₂ × V₂ ÷ C₁. For 1 mL of 10 µM from a 1 mM stock: 10 µM × 1 mL ÷ 1 mM = 10 µL of stock plus 990 µL of diluent.

Can I use different units for the stock and the final solution?

Yes — mM into µM, or mL into µL, is converted for you. Both concentrations must be the same kind (molar with molar, mass with mass). To go between molar and mg/mL, use the Molarity Calculator.

What if the stock volume is too small to pipette?

When the stock volume is under 1 µL, the calculator gives a two-step plan with an intermediate dilution so you can pipette it accurately.

What does a 1:100 dilution mean here?

1 part stock in 100 parts total (1 + 99), the usual lab reading. The dilution factor is C₁ ÷ C₂.