Free Engineering Tool
Power Unit Converter
Convert between all common engineering power units instantly. Enter a value in any unit and see all conversions simultaneously.
This calculator was developed and verified by the Vibromera engineering team, makers of the Balanset portable balancing instruments.
All Conversions
Power from Torque
When torque and rotational speed are known, power is calculated as:
- P — power (kW)
- T — torque (Nm)
- n — rotational speed (RPM)
Conversion Factors to kW
| Unit | Symbol | × Factor = kW | Exact Value |
|---|---|---|---|
| Watt | W | ÷ 1000 | 1 W = 0.001 kW |
| Mechanical Horsepower | hp | × 0.7457 | 1 hp = 745.69987 W |
| Metric Horsepower | PS | × 0.7355 | 1 PS = 735.49875 W |
| BTU per Hour | BTU/h | × 0.000293071 | 1 BTU/h = 0.293071 W |
| Foot-Pound-Force/s | ft·lbf/s | × 0.001355818 | 1 ft·lbf/s = 1.355818 W |
| Kilocalorie per Hour | kcal/h | × 0.001163 | 1 kcal/h = 1.163 W |
Practical Example
Given: 10 hp (mechanical)
kW = 10 × 0.7457 = 7.457 kW
W = 7457 W
PS = 7.457 / 0.7355 = 10.14 PS
BTU/h = 7.457 / 0.000293071 = 25,436 BTU/h
ℹ️ Note: The difference between hp and PS is only ~1.4%. 1 hp = 1.01387 PS. In many practical contexts they are used interchangeably, but for precise engineering work, use the correct conversion.
hp (mechanical horsepower) was defined by James Watt as 550 ft·lbf/s, which equals 745.7 W.
PS (Pferdestärke, German for "horse strength") is the metric horsepower, defined as the power to raise 75 kgf by 1 meter in 1 second, which equals 735.5 W.
1 hp ≈ 1.0139 PS. The difference is ~1.4%. PS is used in Europe and Japan; hp is standard in the US and UK.
Divide kilowatts by 0.7457:
hp = kW / 0.7457
Or multiply by 1.341:
hp = kW × 1.341
Examples: 1 kW = 1.341 hp, 5.5 kW = 7.38 hp, 75 kW = 100.6 hp
BTU/h (British Thermal Units per hour) is a unit of power commonly used in HVAC, heating, and cooling applications.
1 BTU is the energy needed to raise the temperature of 1 pound of water by 1°F.
1 kW = 3,412.14 BTU/h
Air conditioners are often rated in BTU/h — a typical window unit might be 5,000–12,000 BTU/h (1.5–3.5 kW).
Power is torque multiplied by angular velocity:
P (kW) = T (Nm) × n (RPM) / 9549
This means:
- The same power can be achieved with high torque at low speed, or low torque at high speed
- An electric motor rated at 5.5 kW and 1500 RPM produces 35 Nm of torque
- A gearbox trades speed for torque (or vice versa) while (ideally) preserving power
Slightly. Electric horsepower is defined as exactly 746 W. Mechanical horsepower is 745.69987 W.
The difference is only 0.04% — negligible in practice. Electric motor nameplates in the US typically use electric hp, but the distinction rarely matters in engineering calculations.
This converter uses the mechanical hp value (0.7457 kW).
The procedures described on this page were developed and field-tested by the Vibromera team using the Balanset-1A, a portable dual-channel balancer and vibration analyzer for on-site rotor balancing.
Professional field balancing instruments and vibration analysis software. Measure power, torque, and vibration on-site. Used in 50+ countries.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
