Chemistry
Dilution Calculator
Calculate stock volume, diluent volume, dilution factor, and the stock fraction of final volume. The vessel visual shows the measured stock aliquot entering a final-volume flask and the remaining volume supplied by diluent.
Stock solution required (mL)-
Diluent to add (mL)-
Dilution factor-
Stock fraction of final volume-
Decision view
Stock aliquot and final-volume flask
Stock aliquot and final-volume flaskThe measured stock portion and diluent fill one target-volume vessel while C1V1 = C2V2 remains visible.
Exact scenario comparisonTarget concentration changes while all other entered assumptions remain constant.
| Target concentration | Stock solution required (mL) | Diluent to add (mL) | Dilution factor | Stock fraction of final volume |
|---|
How to use Dilution Calculator
- Express stock and target concentration in the same units and basis.
- Enter final solution volume, not the amount of solvent alone.
- Measure the stock aliquot and bring the mixture to final volume using an appropriate vessel.
Calculator guide
Understanding Dilution Calculator
A dilution conserves the modeled amount of solute: C1V1 equals C2V2. Concentration definitions and units must match before the equation is applied.
Calculation method
How the calculation works
Apply C1V1 equals C2V2 to calculate the required stock volume and subtract it from the final volume for diluent quantity. Multiply target concentration by final solution volume and divide by stock concentration for stock volume; subtract that aliquot from final volume for diluent.
Lab workflow
Prepare the solution without confusing solvent and final volume
Adding exactly the calculated diluent is an approximation when volumes are not additive.
Worked situations
Practical examples
- A 2.0-unit stock diluted to 0.25 units at 500 mL requires 62.5 mL stock.
- The remaining nominal diluent volume is 437.5 mL.
- The dilution factor is 8 and stock occupies 12.5% of final volume.
Better inputs
Useful tips
- Use calibrated volumetric equipment at the required precision.
- Account for stock purity and hydration state before defining concentration.
- For serial dilution, calculate and document every intermediate step.
Before relying on the result
Limitations and common mistakes
- The model assumes compatible concentration definitions and additive volumes.
- Purity, chemical reaction, dissociation, density, temperature, contraction, and measurement uncertainty are excluded.
- The target cannot exceed stock concentration without another concentration process.
Reference
Key terms
- Stock concentration
- Concentration of the source solution before dilution.
- Aliquot
- Measured portion removed from the stock solution.
- Final volume
- Total solution volume after stock and diluent are combined.
- Dilution factor
- Stock concentration divided by target concentration.
Important note
Calculated from the entered values using the displayed chemical relationship. Confirm identity, units, purity, conditions, and laboratory safety requirements.
Frequently asked questions
Why is diluent final volume minus stock volume?
That is the additive-volume planning approximation used by this page.
Can molarity and mass percent be mixed?
No. Convert both concentrations to one compatible definition first.
What if calculated stock volume exceeds final volume?
The target is above the stock concentration and cannot be reached by simple dilution.
Does temperature matter?
It can affect volumetric precision and solution volume, though this model does not correct for it.