The Buffer Preparation Reagent Volume Calculator determines how much concentrated stock solution is needed to prepare a target buffer concentration and final volume. It uses the standard concentration-volume relationship, making it useful for routine stock dilution when the stock and target concentrations are expressed in the same units.
Along with the required stock volume, the calculator reports the approximate solvent or diluent volume needed to reach the stated final volume. This is a planning value: in laboratory practice, the final mixture is typically brought to volume after reagents are combined rather than created by assuming volumes are perfectly additive, especially when salts or other components materially change solution volume.
1. Enter stock concentration
Use the concentration of the stock reagent or stock buffer you already have.
2. Enter target concentration
Keep the concentration unit consistent with the stock value.
3. Set final buffer volume
Enter the total volume you want after preparation.
4. Use the stock-volume result
Measure the calculated amount of stock solution.
5. Bring the mixture to final volume
Add solvent or other components as the protocol requires, then adjust to the stated final volume.
Where:
Assumptions: Stock and target concentration units must match. The diluent value is an arithmetic difference; protocols that require bringing a mixture to final volume should follow that practice.
Use 25 mL of the 5 M stock and bring the preparation to a final volume of 250 mL to obtain 0.5 M under the dilution model.
Use the result as a planning or calculation aid and confirm protocol-specific assumptions before laboratory use.
Given
Calculation
V1 = (0.5 × 250) / 5 = 25 mL
Approximate diluent volume = 250 − 25 = 225 mL
Result
25 mL of stock solution.
Interpretation
Use 25 mL of the 5 M stock and bring the preparation to a final volume of 250 mL to obtain 0.5 M under the dilution model.
No. C1 and C2 must use the same concentration basis. Convert one value first if the stock and target are reported differently.
Some mixtures are not perfectly volume-additive. Laboratory protocols often call for bringing the combined solution to a final mark rather than adding an exact arithmetic solvent volume.
A simple dilution cannot produce that result. You need a more concentrated stock, additional solute, or a different preparation method.
Yes. Enter 10 for stock concentration and 1 for target concentration; the ratio is what matters when both values use the same basis.
This calculator determines a stock solution volume. A mass calculator would determine how much solid solute is needed from molecular weight and target molarity.