Final Concentration Calculator
Use this final concentration calculator to find the concentration after dilution. Enter the stock concentration (C₁), the stock volume you add (V₁) and the final total volume (V₂) — it returns the diluted concentration C₂.
Enter the stock concentration, the stock volume you add, and the final total volume to get the concentration after dilution.
How to find the final concentration
When you dilute a stock, the amount of solute is fixed and only the volume grows, so concentration falls in proportion. Rearranging C₁V₁ = C₂V₂ for the final concentration gives:
C₁ is the stock concentration, V₁ is the volume of stock you add, and V_final is the total volume after dilution (stock + solvent). The ratio V_final ÷ V₁ is the dilution factor.
Worked example
You add 5 mL of a 2 M stock and bring the total up to 50 mL: C₂ = (2 × 5) ÷ 50 = 0.2 M — a 10× dilution.
Dilution factor quick reference
For round dilution factors, the resulting concentration is a fixed fraction of C₁ — a fast sanity check on the calculator's answer:
| Dilution factor (V_final ÷ V₁) | Resulting concentration |
|---|---|
| 2× | 50% of C₁ |
| 5× | 20% of C₁ |
| 10× | 10% of C₁ |
| 100× | 1% of C₁ |
| 1000× | 0.1% of C₁ |
Related tools
To instead find how much stock you need for a target strength, use the dilution of solution calculator or the home dilution calculator, which solve C₁V₁ = C₂V₂ for any variable.
Frequently asked questions
›How do I calculate the final concentration after dilution?
Use C₂ = (C₁ × V₁) ÷ V_final, where C₁ and V₁ are the concentration and volume of the stock you add, and V_final is the total volume after dilution. For example, adding 5 mL of 2 M stock to reach a 50 mL total gives C₂ = (2 × 5) ÷ 50 = 0.2 M.
›What is the difference between initial and final concentration?
The initial concentration (C₁) is the strength of your stock before dilution; the final concentration (C₂) is the strength after solvent is added. Diluting always lowers concentration, so C₂ is smaller than C₁ by the dilution factor V_final ÷ V₁.
›Does V_final include the stock volume?
Yes. V_final is the total volume of the mixed solution — the stock plus the solvent you added. If you know the solvent volume instead, add it to V₁ to get V_final before entering it here.
›Is this final concentration calculator free?
Yes. It runs entirely in your browser, needs no sign-up, and never sends your numbers to a server.
›Is there a quick way to estimate the result without the calculator?
Yes — divide C₁ by the dilution factor (V_final ÷ V₁). A 10× dilution always leaves 10% of the original concentration, a 100× dilution leaves 1%, and so on, regardless of the units involved.
Related calculators
Solve C₁V₁ = C₂V₂ for any unknown — stock concentration, volume, or final concentration.
Find molarity from mass and molecular weight, or the mass needed for a target molarity.
Convert between moles, volume, and molar concentration (mol/L) in any direction.
Dilute a solution with C₁V₁ = C₂V₂ — solve for stock volume, final concentration or volume.
Dilute a stock solution to a target concentration with full unit switching.
Convert mg/mL to molarity (and back) using molecular weight — both directions.