Dilution Calculator
M1V1 = M2V2 for any dilution problem.
Enter your values
Enter the stock concentration in M.
Enter the final concentration in M.
Enter the final volume in mL.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Stock volume needed
- 25 mL
- Diluent to add
- 225 mL
- Dilution factor
- 1 : 10
- Fold dilution
- 10×
Working
- 1V₁ = (0.5 × 250) ÷ 5 = 25 mL
Quick answer
Dilution preserves moles of solute, so stock concentration × stock volume equals final concentration × final volume.
M₁V₁ = M₂V₂
At a glance
| What it does | M1V1 = M2V2 for any dilution problem. |
|---|---|
| Category | Science |
| Inputs needed | Stock concentration, Final concentration, Final volume |
| Main output | Stock volume needed |
| Formula | M₁V₁ = M₂V₂ |
| Cost | Free — no sign-up, no download |
How to use the Dilution Calculator
- 1Enter your stock concentration.
- 2Enter the concentration and volume you need.
- 3Read the stock volume and diluent required.
Inputs explained
- Stock concentration(M)
- Enter the stock concentration in M.
- Final concentration(M)
- Enter the final concentration in M.
- Final volume(mL)
- Enter the final volume in mL.
Worked example
Using the values the calculator loads with:
Inputs
- Stock concentration5 M
- Final concentration0.5 M
- Final volume250 mL
Results
- Stock volume needed25 mL
- Diluent to add225 mL
- Dilution factor1 : 10
- Fold dilution10×
- V₁ = (0.5 × 250) ÷ 5 = 25 mL
Frequently asked questions
Do I add stock to water or water to stock?
For acids, always add acid to water. Otherwise add stock to a partial volume of diluent, then top up to the final mark.
What is a serial dilution?
Repeated fixed-factor dilutions, used to reach very low concentrations accurately without measuring tiny volumes.
What do I need to enter into the Dilution Calculator?
Just 3 values: stock concentration, final concentration, final volume. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Dilution Calculator work out the answer?
Dilution preserves moles of solute, so stock concentration × stock volume equals final concentration × final volume. It applies the formula M₁V₁ = M₂V₂ and shows the working so you can check each step by hand.
Is the Dilution Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.