Fuel Pump Flow Rate Calculator
Use this CPR Racing calculator to estimate the fuel volume required for your engine.
Adjust for induction type, fuel density, BSFC, and safety margin.
CPR Racing Fuel Pump Flow Calculator
Enter total engine horsepower at the flywheel.
Sets a typical BSFC starting point.
Approximate fuel density varies by chemistry and temperature.
Manual efficiency adjustment. Typical range: 0.40–0.80.
%
A 15–25% safety margin is commonly used.
Required Fuel Flow
Minimum Flow Rate
170.3 LPH
Minimum Flow (GPH)
45.0 GPH
Mass Flow
225.0 lbs/hr
Base Flow Before Margin
37.5 GPH
Results represent estimated minimum fuel-pump flow at the required operating pressure. Always verify the pump’s published flow curve at your actual base pressure plus boost pressure.
What Is a Fuel Pump Flow Rate Calculator?
This calculator estimates how much fuel your engine needs to support a target horsepower. It converts horsepower and BSFC into fuel mass, then converts that mass into gallons per hour and liters per hour using the selected fuel density.
Fuel Mass = HP × BSFC
Final Flow = Base Flow × Safety Margin
Final Flow = Base Flow × Safety Margin
How to Use the Calculator
- Enter Target Horsepower
Use flywheel horsepower. For wheel horsepower, account for drivetrain loss first. - Select Induction Type
Choose naturally aspirated, supercharged, turbocharged, or race. - Select Fuel Type
The calculator uses fuel density to convert pounds per hour into volume. - Add Safety Margin
Use enough reserve so the pump is not operating at its absolute limit.
Important: This is a sizing estimate, not a substitute for dyno testing or the manufacturer’s pressure-versus-flow chart. Pump flow normally decreases as fuel pressure and electrical load increase.