Solution Dilution Calculator

Find how much stock solution to dilute to a target concentration.

Stock volume needed (V1) (mL) 100
Solvent to add (mL) 400

Formula: C1·V1 = C2·V2 → V1 = C2·V2 ÷ C1

Step-by-step with your numbers:
1. Values used:
2. Stock concentration (C1) = 5 M
3. Final concentration (C2) = 1 M
4. Final volume (V2) = 500 mL
5.
6. Stock volume needed (V1) = 100mL
7. Solvent to add = 400mL
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Work out how much concentrated stock solution and solvent you need to make a diluted solution.

How the Math Works

The Solution Dilution Calculator uses the fundamental dilution equation C1V1 = C2V2, where C1 is the concentrated stock solution concentration, V1 is the volume of stock solution needed, C2 is the desired target concentration, and V2 is the total final volume. This equation expresses the conservation of solute mass: the amount of solute before dilution equals the amount after dilution. By rearranging to V1 = (C2 x V2) / C1, we can solve for the exact volume of stock solution required to achieve our target concentration in the specified final volume.

Practical Applications

To use this calculator practically, first identify your stock solution concentration (C1) and determine your target concentration (C2) and total volume (V2). For example, if you have a 10M stock solution and need 250mL of a 2M solution, plug these values into the formula: V1 = (2 x 250) / 10 = 50mL. You would measure 50mL of the stock solution and dilute it with distilled water to a total volume of 250mL, ensuring the concentrations and volumes are in consistent units.

Day-to-Day Use

This calculation is essential in laboratories, classrooms, and kitchens where precise concentrations matter. In a chemistry lab, students use it to prepare standardized solutions for experiments. Water treatment facilities employ it to adjust chemical dosing. Even in cooking or gardening, understanding dilution helps when concentrating syrups, making plant food solutions, or mixing cleaning products at the correct strength, saving both money and waste while ensuring effectiveness and safety.

Worked example

5 M stock to 1 M in 500 mL → V1 = 1 × 500 ÷ 5 = 100 mL stock + 400 mL solvent.

FAQ

Add acid to water or water to acid?

Always add acid to water (slowly) to safely dissipate heat — never the reverse.