Power Converter
Convert between power units
rate：1 W = 1000 mW
Results in all units
1 W| Unit | Symbol | Value |
|---|---|---|
| Metric | ||
| Watts | W | 1 |
| Milliwatts | mW | 1,000 |
| Kilowatts | kW | 0.001 |
| Megawatts | MW | 0.000001 |
| Gigawatts | GW | 1e-9 |
| Joules/second | J/s | 1 |
| Metric horsepower | PS | 0.00136 |
| Imperial / US | ||
| Mechanical horsepower | hp | 0.001341 |
| BTU/hour | BTU/h | 3.412142 |
| BTU/second | BTU/s | 0.000948 |
| Foot pounds/second | ft·lb/s | 0.737562 |
| Calories/second | cal/s | 0.239006 |
| Kilocalories/hour | kcal/h | 0.860421 |
| Tons of refrigeration | TR | 0.000284 |
About Power Conversion
1 Watts equals 1,000 Milliwatts. The conversion rate is 1 W = 1000 mW. You can switch to any other unit of this category above and see the result instantly.
This converter supports 14 units in total, including Watts, Milliwatts, Kilowatts, Megawatts, and covers metric, imperial and Chinese traditional systems.
Power conversion is frequently used in automotive manufacturing, appliance purchases, and air conditioning. Car enthusiasts compare kilowatts (kW) and horsepower (hp). When choosing AC units, understanding "tons of refrigeration (TR)" is necessary.
All values follow internationally accepted definitions and are rounded to the decimals you choose. The calculation runs entirely in your browser, so nothing is uploaded or stored on a server.
History & Background
The concept of power originated in the Industrial Revolution. After James Watt improved the steam engine, he proposed "horsepower" to demonstrate its efficiency. Later, to honor him, physics named the power of one joule per second a "watt" (W).
Conversion Details
Power conversion is based on the watt (W), representing work done per unit time.
Common conversions: 1 hp ≈ 745.7 W, 1 metric hp ≈ 735.5 W, 1 kW ≈ 1.341 hp.