Electric specs list kW; legacy equipment quotes hp. This guide walks through the kW to HP converter: shaft or electrical power in kilowatts and mechanical horsepower using the standard US conversion factor.
Benefits
- Core formula: HP = kW ÷ 0.7457 (mechanical hp).
- Bridges modern kW ratings with motor and pump nameplates in hp.
- Instant check before comparing VFD, genset, or compressor specs.
How it works
- Enter motor, generator, or load power in kilowatts (kW).
- Apply the mechanical horsepower constant: 1 hp ≈ 0.7457 kW.
- Read horsepower (hp)—the value most US motor plates and catalogs use.
FAQ
How do I convert kW to HP?
HP = kW ÷ 0.7457. Example: 7.5 kW → 7.5 ÷ 0.7457 ≈ 10.06 hp mechanical. Reverse: kW = hp × 0.7457. Use the same constant for three-phase and single-phase when the kW figure is already real power.
What is mechanical horsepower vs. metric hp?
Mechanical horsepower (US) = 0.7457 kW. Metric horsepower (PS, DIN) ≈ 0.7355 kW—common on European auto and small-engine labels. This calculator uses mechanical hp; check the nameplate region before quoting replacement motors.
When do I need kW to hp conversion?
Sizing replacements when the old motor is stamped in hp but the new inverter drive lists kW. Comparing pool pumps, air compressors, and farm equipment across catalogs that mix units. Verifying that a 10 hp nameplate motor matches a 7.5 kW VFD rating line.
Technical specifications
- Mechanical HP = kW ÷ 0.7457.
- kW = HP × 0.7457 (reverse).
- 1 mechanical hp = 745.7 W = 0.7457 kW.
- Related: kw-to-hp, kva-to-kw, amps-to-watts, inverter-sizing.