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💧 Simple Dilution Calculator

Calculate any unknown variable using the C1V1 = C2V2 equation. Enter three values to find the fourth.

Solve for:

C₁ — Stock Concentration

V₁ — Stock Volume to Take

C₂ — Desired Concentration

V₂ — Final Volume Needed

Result

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💡 Important: C₁ and C₂ must be in the same concentration units (they're locked together automatically). V₁ and V₂ can be entered in different volume units (μL/mL/L) — the calculator converts between them automatically.

⚠️ Verify before use: This calculator is a convenience aid. Double-check critical dilutions independently before use in experiments, especially for sensitive reagents or assays.

📖 Example: You have a 10 mg/mL stock solution and need 1 mL of 0.5 mg/mL working solution. Set Solve for = V₁, enter C₁ = 10 mg/mL, C₂ = 0.5 mg/mL, V₂ = 1 mL → answer: take 0.05 mL (50 µL) of stock, add 0.95 mL diluent. Paste this result into your lab notebook or thesis Methods section.

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Any units

Works with mg/mL, μg/mL, molarity, % w/v and more. Keep C and V units consistent.

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Solve any variable

Solve for any of the four variables — C₁, V₁, C₂ or V₂.

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Always free

No sign up, no limits. Calculate as many dilutions as you need.

✔ Formulas last verified against primary references: March 2025 · Report an error

⚠️ Report an incorrect calculation

Frequently asked questions

What's the difference between C1V1=C2V2 and serial dilution?

This single-step dilution equation (C1V1=C2V2) calculates one dilution directly from a stock to a final concentration. Serial dilution instead performs a chain of smaller, sequential dilutions (e.g. 1:10, then 1:10 again) — useful when a single dilution factor would require measuring an impractically small volume of stock.

Do C1 and C2 need to be in the same unit?

Yes — C1 and C2 must share the same concentration unit (e.g. both mg/mL, or both molar) since the equation is a direct ratio. This calculator locks both concentration dropdowns together automatically to prevent unit-mismatch errors. Volumes (V1, V2), however, can be entered in different units (µL/mL/L) since the calculator converts them internally.

Can I solve for the stock concentration instead of the volume?

Yes — select "Solve for = C1" (or any other variable) using the solve-for control, and enter the other three known values. The equation is fully rearranged internally, so any one of the four variables can be calculated from the other three.

Accuracy & how this is derived

Derivation: Direct application of the dilution equation C1V1 = C2V2, which follows from conservation of mass/moles of solute: the amount of solute taken from the stock (C1 x V1) must equal the amount present in the final diluted volume (C2 x V2), since dilution adds only solvent, not additional solute.

Validated against: Fundamental dilution relationship taught and used throughout analytical and general chemistry, biochemistry, and pharmacology laboratory practice.

⚠️ For educational and research support only — verify critical results independently before use in regulated, clinical, or publication-bound work.

✔ Last updated: July 2026 · Report an error

Try next →

🧪 Serial Dilution Calculator ⚖️ Concentration Converter

Simple dilution (C₁V₁ = C₂V₂) in the lab

A dilution calculator applies the conservation equation C₁V₁ = C₂V₂ — the amount of solute is constant when you dilute. Enter any three of the four variables to find the fourth. Useful for preparing working solutions from stock, adjusting assay concentrations, or diluting samples before measurement. Always verify units are consistent: keep volumes in the same unit (µL or mL) and concentrations in the same unit (mg/mL, mol/L) on both sides. A common error is confusing final volume V₂ with the diluent volume to add — the diluent volume = V₂ − V₁. For thesis reporting: state the stock concentration, working concentration, diluent, and final volume. Example: '50 µL of stock (10 mg/mL) was diluted with 950 µL PBS to give a 0.5 mg/mL working solution (1:20, v/v).'