3 W to PS — 3 watts in metric horsepower
Exact 3 ÷ 735.49875 = 0.004078864852
3 watts in other units
| Kilowatts | 0.003 | kW |
|---|---|---|
| Megawatts | 0.000003 | MW |
| Mechanical horsepower | 0.004023066269 | hp |
| Metric horsepower | 0.004078864852 | PS |
| BTU per hour | 10.236425 | BTU/h |
| Foot-pounds per second | 2.212686 | ft·lbf/s |
W to PS at a glance
| Watts | Metric horsepower |
|---|---|
| 1 W | 0.001359621617 PS |
| 2 W | 0.002719243235 PS |
| 3 W | 0.004078864852 PS |
| 5 W | 0.006798108087 PS |
| 10 W | 0.01359622 PS |
| 20 W | 0.02719243 PS |
| 25 W | 0.03399054 PS |
| 50 W | 0.06798108 PS |
| 100 W | 0.13596216 PS |
| 250 W | 0.3399054 PS |
| 500 W | 0.67981081 PS |
| 1,000 W | 1.359622 PS |
How to convert watts to metric horsepower
Multiply by 0.001359621617 — one watt is 0.001359621617 metric horsepower. That factor is exact: it comes from the definition of the units rather than from a measurement, so it will not change and does not need rounding.
Working 3 ÷ 735.49875 = 0.004078864852
What these units are
The watt and the metric horsepower are covered in the power unit guide, along with every other unit on this page.
Questions
How many metric horsepower are in a watt?
One watt is 0.001359621617 metric horsepower. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 3 watts in metric horsepower?
3 watts is 0.004078864852 metric horsepower. The working is 3 ÷ 735.49875 = 0.004078864852.
Why does the same car have two different horsepower figures?
Because there are two horsepowers. Metric horsepower, written PS or CV, is 735.49875 W; mechanical horsepower, written hp or bhp, is about 745.7 W. A car sold as 150 PS in Germany is 148 hp in Britain, and nothing about the engine has changed.
Where does 746 watts come from?
From James Watt, who needed to sell steam engines to people who owned horses. He measured a mill horse turning a wheel and settled on 550 foot-pounds per second — a figure most real horses cannot sustain, which made the comparison flattering to his engines.
How do I read an air conditioner's BTU rating?
BTU ratings are BTU per hour, a rate of heat movement, even when the "per hour" is dropped. A 12,000 BTU/h unit shifts about 3.5 kW of heat. That is not what it draws from the wall — a decent unit moves several times more heat than the electricity it consumes.
What is the difference between power and energy?
Power is a rate, energy is an amount. A kilowatt is how fast something uses energy; a kilowatt-hour is how much it used. A 2 kW heater running for three hours has a power of 2 kW throughout and has consumed 6 kWh. Bills are in energy; ratings are in power.