Electric Motors
Horsepower Kilowatt Calculator
The purpose of Horsepower Kilowatt is to turn mechanical horsepower into mechanical power. Keep the source condition with the saved result so later comparisons remain meaningful.
Inputs for this calculation
Use measurements from one operating condition.
Formula used on this page
For this worksheet, the governing relationship is kilowatts = horsepower × 0.745699872. The participating entries are Mechanical horsepower.
The initial scenario returns 7.457 kW. Re-enter field data before using the answer in a design or comparison.
Convert mechanical horsepower to kilowatts. The permitted service-factor load step is handled by Motor Service Factor Calculator.
Input notes
Record supply arrangement, speed, duty cycle, enclosure, and winding temperature. Do not combine a worst-case value with unrelated nominal data.
Use the displayed unit for every field and document conversions separately. If you also need angular frequency, continue with Angular Frequency Calculator.
- Mechanical horsepower
- Default example: 10 hp. Enter mechanical horsepower in hp.
Applying the result
The calculated Mechanical power is meaningful only with its input conditions attached. Compare it with starting demand, running current, torque, efficiency, slip, and thermal loading.
Label alternate cases rather than overwriting the baseline. For the companion conductance calculation, open Electrical Conductance Calculator.
Where this estimate can fail
Motor electrical input is higher than shaft output because efficiency is below 100%.
Outside the entered variables, consider voltage imbalance, drive waveform, transient torque, and bearing load. Do not hide omitted behavior inside an unexplained correction factor.
Record supply arrangement, speed, duty cycle, enclosure, and winding temperature.
A second scenario
Change Mechanical horsepower from 10 hp to 12 hp while preserving the other measurements. The output changes from 7.457 kW to 8.948 kW.
Keep both cases when the changed input represents genuine uncertainty.
Documenting the calculation
Document mechanical horsepower with mechanical power. Keep enough context to reproduce the result later.
Pass mechanical power as the raw numerical value until the final step. Apply standard sizes only after all checks are complete.
A practical checking sequence
Check the source of mechanical horsepower before calculating. A credible result requires every field to describe the same physical condition and unit basis.
After calculating mechanical power, compare its magnitude with starting demand, running current, torque, efficiency, slip, and thermal loading. An independent order-of-magnitude check can reveal a misplaced decimal or unit prefix.
Keep a baseline and vary the least certain measurement first. A separate analysis may be needed for starting method, service factor, enclosure, and thermal duty.
When the inputs are uncertain
The calculator rejects values outside its stated field limits, but a numerically valid entry can still describe the wrong condition. Confirm mechanical horsepower against the original source before saving the result.
Use an additional case for load inertia, acceleration profile, harmonics, reduced-speed cooling, and mechanical loss when that behavior is not negligible. Keep the baseline intact so the effect of each changed assumption remains visible.