Operator calculator
Filter Loading Rate calculator
Divide flow by filter surface area for gpm per square foot.
Calculator
Loading rate
2 gpm/ft²
- 1. 900 gpm ÷ 450 ft² = 2 gpm/ft²
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
loading rate (gpm/ft²) = flow (gpm) ÷ filter area (ft²)
| Input | Unit |
|---|---|
| Flow | gpm |
| Filter surface area | ft² |
| Result: Loading rate | gpm/ft² |
When to use it
Loading rate is how much water each square foot of filter surface passes. Operators watch it to keep filters inside their design range.
Surface area is length times width, so many questions give the filter dimensions rather than the area.
Applies to: Water Treatment.
Exam tip: Area first, rate second. Write the area down before you divide.
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