Skip to main content
An independent exam-prep resource.
Certification prep for water and wastewater operatorsPremium

Operator calculator

Dilution (C₁V₁ = C₂V₂) calculator

Find the diluted concentration when a solution is made up to a larger volume.

Calculator

Final concentration

1,000 same unit as C₁

  1. 1. C₂ = (50,000 × 10) ÷ 500 = 1,000

For instructional use. Results assume the standard conversion factors shown on this page. Actual field calculations may need chemical strength, density, temperature, and other adjustments, so check your plant’s procedures.

Formula and inputs

C₂ = (C₁ × V₁) ÷ V₂

InputUnit
Starting concentration (C₁)mg/L or %
Starting volume (V₁)any volume unit
Final volume (V₂)same unit as V₁
Result: Final concentrationsame unit as C₁

When to use it

Dilution keeps the amount of chemical the same while the volume grows, so concentration drops in proportion.

C₁V₁ = C₂V₂ works with any matching units. Just make sure both volumes use the same unit and both concentrations use the same unit.

Applies to: Water Treatment, Wastewater Treatment.

Exam tip: The answer must be smaller than the starting concentration. If it is larger, you flipped the volumes.

Study guides

Build the math skill behind the calculator

Water Operator Math Made Simple walks through the formulas step by step.

Water Operator Math Made Simple ebook cover

Water Operator Math Made Simple

A Step-by-Step Guide to the Math Every Water Operator Needs to Know