How power conversion works
Every power unit has a fixed ratio to the watt. The value is first converted to watts, then into the target unit.
Common values
| Value (PS) | Result |
|---|---|
| 0.1 PS | 0.0735499 kW |
| 0.25 PS | 0.183875 kW |
| 0.5 PS | 0.367749 kW |
| 1 PS | 0.735499 kW |
| 1.5 PS | 1.10325 kW |
| 2 PS | 1.471 kW |
| 3 PS | 2.2065 kW |
| 5 PS | 3.67749 kW |
| 10 PS | 7.35499 kW |
More detail
hp vs PS — same word, different watts
Mechanical horsepower (hp) is defined as 745.7 W, while metric horsepower (PS, from "Pferdestärke"/"cheval-vapeur") is 735.5 W — so the same engine rated in PS shows a slightly higher number than in hp. Modern international specs increasingly use kW. BTU/h is the common unit for air-conditioner cooling capacity.
Two kinds of horsepower. 1 metric horsepower (PS) ≈ 735.5 W but 1 mechanical horsepower (hp) ≈ 745.7 W — about 1.4% apart. Check which one a spec sheet means before comparing cars across markets.
Frequently asked questions
How many watts is 1 horsepower?
Mechanical horsepower (hp) = 745.7 W. Metric horsepower (PS) is defined differently at 735.5 W, so the same engine reads a slightly higher number in PS than in hp.
What's the difference between hp and PS?
Mechanical horsepower (hp) = 745.7 W; metric horsepower (PS, from German "Pferdestärke") = 735.5 W. Some markets' car spec sheets use PS, but international standards increasingly use kW.
How many watts is 1 BTU/h?
1 BTU/h ≈ 0.29307 W. For example, a 5,000 BTU/h air-conditioner cooling capacity is about 1,465 W (≈1.465 kW).
How many horsepower is 1 kW?
1 kW ≈ 1.341 hp (mechanical) or ≈ 1.360 PS (metric).