# Power converter

> Power measures the rate of energy transfer. This converter handles all common power units — from milliwatts to megawatts, mechanical horsepower to metric PS, BTU per hour to.

Convert between watts, kilowatts, megawatts, horsepower, PS, BTU per hour, and more power units instantly.

**Interactive version:** https://onlinecalculator.me/unit-converters/power/
**Category:** Unit Converters

## Key conversions

| Unit | Equivalent in watts |
|---|---|
| 1 kW | 1,000 W |
| 1 MW | 1,000,000 W |
| 1 HP (mechanical) | 745.7 W |
| 1 PS (metric HP) | 735.5 W |
| 1 BTU/hr | 0.293 W |
| 1 kcal/hr | 1.163 W |

## Example

1 kW to horsepower: 1,000 ÷ 745.7 ≈ **1.341 HP**

## Frequently asked questions

### What is the difference between HP and PS?

Mechanical horsepower (HP) = 745.7 W. Metric horsepower (PS, from German Pferdestärke) = 735.5 W. They are close but not identical — a 200 HP engine is 200 × 745.7 = 149,140 W; 200 PS is 147,100 W.

### How many watts in one horsepower?

1 mechanical HP = 745.69987 W. 1 PS = 735.49875 W. Both are close to 0.75 kW.

### What is a BTU per hour?

BTU/hr is a heat transfer rate common in HVAC. 1 BTU/hr = 0.293 W; a 12,000 BTU/hr air conditioner is 3,516 W (3.5 kW).

### How do I convert watts to kilowatts?

Divide by 1,000. 1 kW = 1,000 W.

### How do I share my conversion?

Click "Share with my numbers" to copy a URL with your units and value.

## Sources

- [Watt — SI unit of power](https://en.wikipedia.org/wiki/Watt) — Wikipedia
- [Horsepower — definition and watt conversions](https://en.wikipedia.org/wiki/Horsepower) — Wikipedia
- [NIST Special Publication 811: Guide for the Use of the SI (conversion factors)](https://www.nist.gov/pml/special-publication-811) — National Institute of Standards and Technology

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