Precise Dilution Calculator
This dilution calculator applies the C1V1 = C2V2 relationship so you can convert a concentrated stock solution into a weaker working batch without guessing. Enter the concentrate strength, the strength you want to use, and how much working solution you need, and the calculator shows exactly how much concentrate and diluent to combine.
Understanding Dilution Math
The calculation uses C1V1 = C2V2. C1 is the concentrate strength, V1 is the concentrate volume you must measure out, C2 is your desired working strength, and V2 is the total batch size. Solving for V1 gives V1 = (C2 × V2) / C1. Subtract V1 from V2 to find how much diluent (often water or buffer) to add.
- Always convert percentages to the same units before calculating.
- Use milliliters or liters consistently across all volume inputs.
- V1 will always be smaller than V2 because the working solution is weaker than the concentrate.
Example: Hospital Surface Disinfectant
A facilities manager has a 12% sodium hypochlorite concentrate and needs 2,000 mL of a 0.5% working solution for daily fogging. Enter 12 in Concentrate Strength, 0.5 in Desired Working Strength, and 2000 in Target Batch Volume. The calculator returns 83.33 mL of concentrate and 1,916.67 mL of diluent, which is a 1 : 22.99 ratio. Mixing those amounts yields the required 2 L of 0.5% disinfectant without overshooting the active ingredient.