Dilution Calculator — C1V1 = C2V2 Solver

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The lab's favorite equation — solve C1V1 = C2V2 for whatever you're missing.

Solve for Volume of stock needed (V1) Final volume to prepare (V2) Achieved concentration (C2)

C1 (stock conc.)

V1 (stock volume)

C2 (target conc.)

V2 (final volume)

How to use this tool

1. Choose what to solve for — that field is disabled and the others feed it.
2. Enter the known values — keep units consistent (all mL, or all L; all M or all mg/mL).
3. Press Calculate — the answer includes the practical instruction (how much stock, how much diluent).

Example

10 M stock into 0.5 M, final volume 100 mL: V1 = 100 × 0.5 ÷ 10 = 5 mL stock + 95 mL water — a 1:20 dilution.

The formula

C1 × V1 = C2 × V2 (the amount of solute is identical before and after diluting)

What the result means

Dilution conservs solute: whatever molecules were in the stock are all still there after you add water — spread through a bigger volume, hence a smaller concentration. The dilution factor (C1/C2) tells you the ratio at a glance, which is how bench protocols are usually written ('make 1:20').

Frequently asked questions

Does it matter which units I use?

Only consistency does: V1 and V2 in the same unit, C1 and C2 in the same unit. The equation is pure ratios.

Why does 5 mL stock + 95 mL water, not + 100 mL?

Because the final volume is what counts. 5 mL + 95 mL = 100 mL total; adding 100 mL of water would give 105 mL and a wrong concentration — the classic beginner's error.

Can it handle serial dilutions?

Not in one step — compute each stage separately, chaining the output C2 into the next C1. That's also the honest way to catch pipetting-error accumulation.

Is this lab data uploaded?

No — everything is computed in your browser.

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