kW to HP Converter
| kW | hp | PS | Motor |
|---|---|---|---|
| 2 kW | 2.7 hp | 2.7 PS | shop welder |
| 5 kW | 6.7 hp | 6.8 PS | bench table saw |
| 7.5 kW | 10.1 hp | 10.2 PS | small air compressor |
| 75 kW | 100.6 hp | 102 PS | city bus |
| 150 kW | 201.2 hp | 203.9 PS | warm EV hatchback |
| 400 kW | 536.4 hp | 543.8 PS | performance V8 |
| 1,000 kW | 1341 hp | 1359.6 PS | hypercar tier |
One factor carries every motor nameplate: mechanical horsepower = kilowatts x 1.341. The European spec sheet says your car makes 150 kW; the American review says 201 hp; both are the same machine, one factor apart. Type either figure and the converter fills in the other live - with a toggle for metric horsepower (PS), which runs seven percent higher and confuses half the brochures on the internet.
The two units are legacies that refuse to die: horsepower was James Watt's marketing arithmetic (a horse, a mill wheel, and a number generous to his engines), kilowatts are what the electrical world actually measures. They meet everywhere now - EV motor specs in kW, performance brochures in hp, generator plates in either. The table below carries the motors people actually convert, from shop welders to hypercars, so the anchor numbers stay honest.
How to use
- Type the kilowatts from the motor plate, EV spec or generator label - horsepower appears instantly, or run it backwards from a hp figure.
- Toggle PS if the source is a European brochure - metric horsepower is 735.5 W, not 745.7, and the difference is 1.4 percent of bragging rights.
- Sanity anchor: 0.746 kW per hp, so a 5 kW welder is about 6.7 hp and a 100 kW EV motor is about 134.
Frequently asked questions
How many hp is 100 kW?
About 134 mechanical horsepower: 100 x 1.341. In metric horsepower the same motor reads 136 PS - both answers describe one motor, and the seven percent gap between the two horsepower flavors explains most of the arguments under European car videos. The converter's toggle switches between the flavors so the numbers stay comparable.
Why are there two kinds of horsepower?
Two committees standardized the horse differently. Mechanical (or imperial) horsepower is 745.7 watts - Watt's original mill-horse arithmetic fossilized; metric horsepower, called PS from the German Pferdestärke, is 735.5 watts - the power to lift 75 kilograms one meter in one second. Cars built for the EU market quote PS, US reviews quote hp, and the same engine gains or loses three or four horsepower crossing the Atlantic without changing at all.
Why do electric cars state power in kW?
Because electric motors ARE electrical devices - their nameplates speak the grid's language. A 150 kW EV motor equals about 201 hp; the battery's 77 kWh is energy (what it stores), the motor's 150 kW is power (how fast it can use it), and confusing the two is the EV-era version of the megabit confusion. Charging speeds and motor output are both quoted in kW for the same reason.
How do I convert hp back to kW?
Divide by 1.341, or multiply by the cleaner 0.7457 - one horsepower is exactly 745.7 watts by modern definition. A 6.7 hp shop welder draws about 5 kW; a 400 hp V8 produces about 298 kW at the crank. The converter runs both directions live, and the PS toggle covers the metric variant for European brochures.
Is horsepower still measured with horses?
No - it has been a fixed unit for a century: 745.7 watts, definitionally. Watt's original 1780s arithmetic (a mill horse turning a walk for ten hours) was generous to his engines and optimistic about horses, but the number is now pure definition - a horse today would test at roughly 15 hp in a sprint. The horse left the unit; the marketing survived.