Power-to-weight calculator

Choose power and mass units, then enter values measured on a consistent basis. Include occupants and cargo if comparing loaded vehicles. Mechanical horsepower and metric horsepower are different units.

100 kW with a mass of 1000 kg gives 100 kW per tonne. With mechanical horsepower, 200 hp and 3000 lb gives 15 lb per hp.

Power per tonne = power(kW) / mass(kg) × 1000

Reference: NIST SI conversion factors

The result above uses these exact values. This snapshot is included when the page is printed so the output can be checked against the original measurements.

Power unit

kW

Power

100 kW

Mass unit

kg

Vehicle mass

1000 kg

Primary result: Power per tonne: 100 kW/t.

• Measure from the datum or reference edge described by this tool, and do not mix inside, outside and centerline dimensions.
• Keep inputs in the displayed units and preserve more precision than the final cutting or purchasing tolerance requires.
• When the result is close to a limit, verify it with a test piece, field measurement, manufacturer drawing or qualified project professional.

A higher power-to-mass ratio does not by itself predict acceleration or top speed. Gearing, traction, aerodynamic drag and drivetrain losses matter. Compare engine power with engine power, or wheel power with wheel power.