Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Stock volume needed (mL)
10.000
Diluent to add (mL)
90.000
Dilution factor (×)
10.00
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter stock concentration (c1).
- 2Enter target concentration (c2).
- 3Enter final volume (v2) (mL).
- 4Read your stock volume needed (ml) on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
The workhorse of any lab bench: figure out how much stock solution and how much diluent to combine for the concentration you actually want.
Worked example
Using the values the calculator loads with:
Inputs
- Stock concentration (C1): 10
- Target concentration (C2): 1
- Final volume (V2): 100 mL
Results
- Stock volume needed (mL): 10
- Diluent to add (mL): 90
- Dilution factor (×): 10
What each field means
Inputs
- Stock concentration (C1)
- The stock concentration (c1) used in the calculation. Starts at 10 so you have a working example on load.
- Target concentration (C2)
- The target concentration (c2) used in the calculation. Starts at 1 so you have a working example on load.
- Final volume (V2) (mL)
- The final volume (v2) used in the calculation, measured in mL. Starts at 100 mL so you have a working example on load.
Results
- Stock volume needed (mL)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Diluent to add (mL)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Dilution factor (×)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the dilution calculator work?
The workhorse of any lab bench: figure out how much stock solution and how much diluent to combine for the concentration you actually want. The underlying maths is: C1 × V1 = C2 × V2
What do I need to enter?
3 values: stock concentration (c1), target concentration (c2), and final volume (v2). Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the stock volume needed (ml) result mean?
It is returned as a decimal number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are rounded for display; the underlying calculation keeps full precision.
Who is this tool for?
It's built for students, developers, and anyone who needs the answer right now without setting up a spreadsheet.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Dilution Calculator (C1V1 = C2V2). Retrieved from https://www.revenuelab.fyi/toolbox/dilution
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/dilution" target="_blank" rel="noopener">Dilution Calculator (C1V1 = C2V2) — RevenueLab</a> (2026).</p>
Source: [Dilution Calculator (C1V1 = C2V2) — RevenueLab](https://www.revenuelab.fyi/toolbox/dilution) (2026).