How It Works
This calculator works in 4 steps.
Enter the stock concentration (C₁)
Type the concentration of the material on hand.
Enter the stock volume (V₁)
Type the full volume to be used, such as a 1 mL vial.
Enter the target concentration (C₂)
Type the working concentration in the same unit as C₁.
Read the final volume (V₂)
The calculator returns V₂ = C₁V₁ / C₂ and the diluent volume to add.
The Formula
The formula divides the solute amount in the stock portion by the target concentration.
V₂ = (C₁ × V₁) / C₂V_diluent = V₂ − V₁- V₂:
- Total volume at the target concentration
- C₁:
- Stock concentration
- V₁:
- Available stock volume
- C₂:
- Target concentration
A 2 mL vial of 1 M stock diluted to 0.1 M gives V₂ = 1 × 2 / 0.1 = 20 mL. Add 18 mL of diluent.
Conversion Table
The conversion table lists the final volume and diluent needed for 6 fixed stock portions.
| Stock (C₁) | Stock volume (V₁) | Target (C₂) | Final volume (V₂) | Diluent to add |
|---|---|---|---|---|
| 10 mM | 5 mL | 1 mM | 50 mL | 45 mL |
| 1 M | 2 mL | 0.1 M | 20 mL | 18 mL |
| 50 mg/mL | 1 mL | 2 mg/mL | 25 mL | 24 mL |
| 100 µg/mL | 0.5 mL | 5 µg/mL | 10 mL | 9.5 mL |
| 37 % | 10 mL | 3 % | 123.3 mL | 113.3 mL |
| 20 µM | 0.25 mL | 0.5 µM | 10 mL | 9.75 mL |
What Is the Final Volume Calculator?
The Final Volume Calculator is a dilution tool that returns the total volume (V₂) a known amount of stock reaches at a target concentration. The tool fits cases where the stock volume is fixed, such as an entire vial, a leftover aliquot, or a single-use ampoule.
The result tells the user how much working solution one portion of stock yields. The calculator reports V₂ and the diluent volume (V₂ − V₁) in mL, L, and US fluid ounces (fl oz) for larger batches.
Common Uses
There are 5 main uses of this calculator.
Whole-vial dilution
Users dilute an entire lyophilized or liquid vial without splitting it.
Working solution yield
Technicians see how many assays one stock aliquot supports.
Container selection
Staff pick a 50 mL tube or a 1 L (33.8 US fl oz) bottle before mixing.
Leftover stock use
Labs dilute a remaining aliquot to a usable concentration rather than discarding it.
Batch sizing
Production teams size a batch from a fixed concentrate delivery.