Operator calculator
Percent Strength of a Solution calculator
Find pounds of chemical in a tank of solution from its volume and percent strength.
Calculator
Chemical
521.25 lb
- 1. 12.5% ÷ 100 = 0.125
- 2. 500 gal × 8.34 × 0.125 = 521.25 lb
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
lb chemical = volume (gal) × 8.34 lb/gal × (percent strength ÷ 100)
| Input | Unit |
|---|---|
| Solution volume | gal |
| Percent strength | % |
| Result: Chemical | lb |
Conversion factors used: 8.34 lb per gallon of water; 1% = 10,000 mg/L.
When to use it
A one percent solution holds 10,000 mg/L of chemical. Percent strength questions ask how many pounds of actual chemical you have in a given volume.
Convert the percent to a decimal, then multiply by the weight of the water, using 8.34 lb/gal.
Applies to: Water Treatment, Water Distribution, Wastewater Treatment.
Exam tip: Percent to decimal means divide by 100. 12.5% is 0.125.
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
A Step-by-Step Guide to the Math Every Water Operator Needs to Know