BSFC Calculator

Written by Great Medico

Updated September 26, 2026 •1 min read

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The Brake-Specific Fuel Consumption Calculator relates fuel mass flow to useful engine power.

Formula

BSFC = fuel mass flow ÷ brake power, reported here in g/kWh. If power is not known directly, the calculator can derive it from torque and engine speed using P = τω.

Efficiency

Choose a fuel to use its published energy density, or enter a custom value. Estimated efficiency = 100 ÷ (energy density × BSFC).

Example

A fuel flow of 14.78 g/s at 250 kW gives about 212.83 g/kWh. With gasoline’s energy density used by this model, estimated efficiency is about 38.96%.