⛽ Fuel Pump Calculator
Enter your target horsepower to estimate the minimum fuel pump flow rate your engine build needs.
Why fuel pump sizing matters
An undersized fuel pump can starve an engine of fuel under high load, causing a dangerously lean condition. Sizing a pump correctly starts with knowing how much fuel your target horsepower actually requires.
The formula
This calculator uses Required Fuel Flow = Horsepower × BSFC (Brake Specific Fuel Consumption), then adds a safety margin to account for pump wear, voltage drop, and fuel pressure fluctuation. The result is shown in pounds per hour as well as liters per hour and cc/min for comparing against pump and injector spec sheets.
This is a general sizing estimate based on a typical BSFC value — actual requirements vary with fuel type, forced induction, and tune. Always cross-check against your specific pump and injector manufacturer specifications before building a fuel system.