⛽ BSFC Calculator
Enter your engine’s fuel flow rate and horsepower output to calculate Brake Specific Fuel Consumption (BSFC).
What is BSFC?
Brake Specific Fuel Consumption (BSFC) measures how efficiently an engine converts fuel into power. It tells you how much fuel is consumed per unit of horsepower produced over an hour, making it a standard way to compare engine efficiency independent of engine size.
The formula
BSFC = Fuel Flow Rate ÷ Horsepower, typically expressed in pounds of fuel per horsepower per hour (lb/hp/hr). A lower BSFC means the engine extracts more power from each pound of fuel burned. This calculator also converts the result to kilograms per kilowatt-hour, a common metric unit.
Typical gasoline engines fall roughly between 0.35 and 0.60 lb/hp/hr depending on load, tuning, and fuel type. This tool is for general reference and educational purposes; real BSFC varies with RPM, load, and air/fuel ratio.