Brake-Specific Fuel Consumption Calculator

Enter fuel mass flow rate and brake power to calculate BSFC in g/kWh and lb/hp·h — the standard metric for comparing engine fuel efficiency.

Engine Parameters

BSFC Result

BSFC (SI / Metric)
— g/kWh
grams per kilowatt-hour
BSFC (SAE / Imperial)
— lb/hp·h
pounds per horsepower-hour
Efficiency Context

Enter values to see efficiency rating

Formula
BSFC (g/kWh) = Fuel Flow (g/h) ÷ Power (kW)
lb/hp·h = g/kWh × 0.001644

Typical BSFC Values by Engine Type

Engine Type BSFC (g/kWh) BSFC (lb/hp·h) Example
NA Gasoline (peak torque) 270–320 0.44–0.53 1.6 L DOHC
Turbocharged Gasoline (GDI) 220–260 0.36–0.43 2.0T EA888
Turbo Diesel (passenger car) 190–215 0.31–0.35 2.0 TDI CR
Heavy-Duty Diesel (optimized) 165–190 0.27–0.31 MAN D26 / Cummins X15

Click any row to load example values into the calculator.

Summary

Enter fuel mass flow rate and brake power to calculate BSFC in g/kWh and lb/hp·h — the standard metric for comparing engine fuel efficiency.

How it works

  1. Enter the fuel mass flow rate in your preferred unit (g/s, kg/h, or lb/h).
  2. Enter the brake power output in kW or hp.
  3. The calculator converts all inputs to SI base units (g and kW).
  4. BSFC (g/kWh) = (Fuel Flow g/h) ÷ Power (kW).
  5. The imperial equivalent lb/hp·h is computed via the fixed conversion factor: 1 g/kWh = 0.001644 lb/hp·h.
  6. Results are compared against typical BSFC benchmarks for common engine families.

Use cases

  • Benchmark a new engine build against OEM fuel-efficiency targets.
  • Compare gasoline and diesel powertrains at a given operating point.
  • Evaluate the effect of tuning changes (cam, compression, injection) on fuel efficiency.
  • Validate engine simulation (1D/3D CFD) output against measured dyno data.
  • Academic coursework on internal combustion engine thermodynamics.
  • Calculate operating cost differences between engine variants at a given load point.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu