Online Tool Store
Power Converter
Convert power between watts, kilowatts, and horsepower instantly, with all three units synced live as you type. Runs entirely in your browser.
This works right here on your device — nothing gets sent out.
Example shown — edit any field, the other three update instantly. Horsepower means mechanical horsepower.
How it works
- Type a value into Watts, Kilowatts, Horsepower, or BTU per hour.
- The other three fields update instantly as you type.
- Clear a field to clear all four and start over.
The formula
All four units convert through watts, the SI unit for power. Horsepower here means mechanical horsepower:
Kilowatts = Watts / 1,000
Horsepower = Watts / 745.699872
BTU/h = Watts / 0.29307107
Example: 1,000 W is exactly 1 kW, about 1.341 mechanical hp, and about 3,412.14 BTU/h.
FAQ
Does anything I type get sent anywhere?
No. The conversion is a simple multiplication done locally in your browser — nothing is uploaded.
Which horsepower is this — mechanical, metric, or electrical?
Mechanical (imperial) horsepower, the most common definition: 1 hp = 745.7 W. Metric horsepower (PS), used in parts of Europe, is very slightly smaller at 735.5 W — for everyday conversions the difference is under 1.5% and usually doesn't matter, but keep it in mind if you need an exact match to a spec sheet that uses PS.
Can I enter a negative number?
No — power in this context is a magnitude, so negative values are rejected with an error rather than converted.
Why do the numbers have so many decimal places sometimes?
Converting to or from horsepower involves dividing by 745.699872, which rarely produces a clean round number — the result is shown at full precision rather than rounded, so you get the exact converted value.
How we compare
| Feature | Online Tool Store | Google "convert" search | RapidTables |
|---|---|---|---|
| No file upload — runs in your browser | ✓ | ✓ | ✓ |
| All three units editable and synced at once | ✓ | One pair per search | One pair per page |
| No ads | ✓ | ✓ | Ad-supported |
A quick Google search or RapidTables can convert one unit pair at a time, but you're stuck re-searching or scrolling to a different table for the next unit. Power Converter keeps all three in view and in sync, so you see watts, kilowatts, and horsepower together from a single number.