Power Unit Converter
Convert between every power unit in one place. Pick any two units, see the exact factor and the worked calculation.
How to use it
- Choose the unit you have and the unit you want.
- Type a value — the conversion is instant and shows the working underneath.
- Swap flips the two units. The URL always reflects what you see.
This converter covers every common power unit in one page rather than one fixed pair, so you are not hunting for a specific "X to Y" page when the two units you need are not the ones most people search for.
Pick the unit you have, the unit you want, and type a value — the result and the conversion factor both update immediately, worked out to full precision rather than a rounded rule of thumb.
Power units on this page
| Unit | Symbol | Notes |
|---|---|---|
| Milliwatt | mW | Laser pointers, radio transmit power and low-power electronics. |
| Watt | W | Light bulbs, appliances, audio equipment and solar panels. |
| Kilowatt | kW | Heaters, EV chargers, motors and domestic electricity supply. |
| Megawatt | MW | Wind turbines, data centres and small power stations. |
| Gigawatt | GW | National grid capacity and large power stations. |
| Horsepower (mechanical) | hp | Car and engine ratings in the US and UK. |
| Brake horsepower | bhp | Car specifications, where it typically reads higher than wheel horsepower. |
| Horsepower (metric) | hp(M) | European vehicle ratings, often written PS or CV. |
| BTU per hour | BTU/hr | Air conditioning, heating and boiler ratings. |
| Refrigeration ton | RT | Commercial air conditioning and chiller capacity. |
| Decibel-milliwatts | dBm | Radio, Wi-Fi signal strength and fibre optics. |
A worked example
1 mW = 0.0000013410221 hp. That factor comes from each unit's fixed relationship to the dimension's base unit — nothing here is approximated or looked up from a rounded table.
Every pairing on this page uses the same approach, so a chain of conversions (say, millimetres to miles) stays accurate rather than compounding rounding error the way repeated approximate factors would.
Everything runs in your browser
There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.
Last updated 18 August 2026