The short answer: 55 horsepower comes to 41.01349294 kW. That is 55 multiplied by 0.7456998716, the factor fixed by definition, carried to full precision before anything is rounded for display.
41.0135 kW is 55 mechanical horsepower and 55.76 metric PS. Put that through a 1,400 kg car at 80% drivetrain efficiency and the energy needed to reach 100 km/h — 540.1 kJ — takes about 16.5 seconds to deliver, which is a floor rather than a real figure because it ignores drag and traction limits.
The result sits 1.013 kW past 40 kW, so if you need a round figure to quote, 40 kW is the honest nearest one. Plenty of people do this in their head: divide by 1.3 instead of using the exact factor 0.7456998716. At 55 that shortcut gives 42.307692 kilowatts, off by 1.294 kilowatts or about 3.16%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
The formula
55 hp- The quantity being converted
0.7456998716- Exact kilowatts in one horsepower
41.01349294 kW- The converted result
How it works, step by step
- Start with 55 horsepower.
- Multiply by 0.7456998716, the exact number of kilowatts in one horsepower.
- That gives 41.013492937 kilowatts.
- The reverse works the same way with division: 41.01349294 kW ÷ 0.7456998716 = 55 hp.
Worked examples
The calculation
Because this is a straight proportion, 55 hp × 0.7456998716 = 41.013492937 kW — no offset, no second term, nothing else to account for.
Checking it backwards
Divide the answer back: 41.01349294 kW ÷ 0.7456998716 returns 55 hp. If a converter fails this test it has inverted the factor, which is the single most common conversion error there is.
How to read your score
Frequently asked questions
What is 55 horsepower in kilowatts?
The answer is 41.01349294 kW — or 41.013492937 kilowatts before any rounding.
How do you convert horsepower to kilowatts?
One step: multiply the horsepower figure by 0.7456998716. Here that is 55 × 0.7456998716 = 41.01349294 kilowatts.
What is 41.01349294 kilowatts back in horsepower?
55 horsepower. Dividing by 0.7456998716 undoes the conversion exactly.
Is 55 hp a lot?
41.0135 kW is 55 mechanical horsepower and 55.76 metric PS. Put that through a 1,400 kg car at 80% drivetrain efficiency and the energy needed to reach 100 km/h — 540.1 kJ — takes about 16.5 seconds to deliver, which is a floor rather than a real figure because it ignores drag and traction limits. The reference table shows the values either side of it for comparison.
What is a horsepower?
Mechanical horsepower, defined by James Watt as 550 foot-pounds per second.
What is a kilowatt?
The rating unit for motors, EV chargers and solar arrays.
55 hp in kilowatts — nearby values
| Horsepower | Kilowatts | Unrounded |
|---|---|---|
| 49 hp | 36.539294 | 36.53929371 |
| 50 hp | 37.284994 | 37.28499358 |
| 51 hp | 38.030693 | 38.03069345 |
| 52 hp | 38.776393 | 38.77639332 |
| 53 hp | 39.522093 | 39.52209319 |
| 54 hp | 40.267793 | 40.26779307 |
| 55 hp | 41.013493 | 41.01349294 |
| 56 hp | 41.759193 | 41.75919281 |
| 57 hp | 42.504893 | 42.50489268 |
| 58 hp | 43.250593 | 43.25059255 |
| 59 hp | 43.996292 | 43.99629242 |
| 60 hp | 44.741992 | 44.74199229 |
| 61 hp | 45.487692 | 45.48769217 |
Exact factor: 1 horsepower = 0.745699871582 kilowatts. The row for 55 hp is the value this page is about.