Power Converter — Watts, Horsepower, BTU/h & More
Convert between watts, horsepower (mechanical, electric, metric), BTU per hour, and more. Free online power unit converter for engines and appliances.
Power Converter
Results update instantly as you type
Enter Values
Embed Code
Copy and paste this HTML snippet into any web page to embed this calculator directly.
<iframe src="http://127.0.0.1:54963/embed/industrial/power-converter?ref=embed" title="Power Converter — Watts, Horsepower, BTU/h & More" width="100%" style="max-width:600px; border:none; height:500px;" loading="lazy"></iframe>
Direct Link
Share this link to let others open the calculator in their browser.
The Formula
Power conversion uses linear factors relative to the Watt (W), the SI base unit of power. One watt equals one joule per second. Different horsepower variants reflect historical measurement standards — mechanical horsepower (745.7 W) was defined by James Watt, electrical horsepower (746 W) is used for electric motors, and metric horsepower (735.5 W) is the European standard.
Variable Definitions
Power
The rate at which energy is transferred or converted, measured in watts (W) or horsepower (hp). One watt = one joule per second.
SI Power Units (Watt & Kilowatt)
Watt: one joule per second. A typical LED bulb uses 10 W. Kilowatt (1,000 W): the standard unit for electrical appliance ratings and EV motor output. 1 hp ≈ 0.746 kW.
One Mechanical Horsepower
745.7 watts. Defined by James Watt as the power a draft horse can sustain. The standard rating for US vehicle engines.
How to Use This Calculator
- 1
Enter the power value you want to convert in the "Value" field.
- 2
Select the current power unit from the "From" dropdown (e.g., hp for engine power, kW for electrical).
- 3
Select the desired power unit from the "To" dropdown.
- 4
The converted value appears instantly. Use this to compare engine specs, appliance ratings, or industrial equipment across different unit systems.
- 5
Check the quick reference table for common power comparisons like engine horsepower to kilowatts or BTU/h to watts.
Quick Reference
| From | To |
|---|---|
| 1 hp (mechanical) | 745.7 W / 0.746 kW |
| 1 kW | 1.341 hp / 3,412 BTU/h |
| 1 hp (metric) | 735.5 W |
| 1 hp (electric) | 746 W |
| 1 BTU/h | 0.293 W |
| 1 MW | 1,341 hp / 1,000 kW |
| 1 ft·lbf/s | 1.356 W |
| 1 kcal/s | 4,184 W / 4.184 kW |
Common Applications
- Compact car engine: 100–200 hp (75–150 kW)
- Mid-size car engine: 200–350 hp (150–260 kW)
- Household microwave: 700–1,200 W
- Central AC unit: 3,500–5,000 W (12,000–18,000 BTU/h)
- Electric vehicle motor: 100–300 kW (134–402 hp)
- Data center server rack: 5–15 kW per rack
Power ratings span from watts (LED bulb) to megawatts (power plant) — nine orders of magnitude
Understanding the Concept
Power measures how quickly work is done — the rate of energy transfer. The SI unit is the watt (W), where one watt equals one joule per second. Horsepower (hp) is the imperial standard, originally defined by James Watt (of steam engine fame) to market his improved steam engines by comparing them to draft horses. Today, power ratings appear everywhere: vehicle engines (hp or kW), electrical appliances (watts), motors (hp), HVAC systems (BTU/h), and industrial machinery (kW or MW). Electric vehicle motors are typically rated in kW (a Tesla Model 3 Performance produces about 450 kW ≈ 603 hp). Understanding power conversion helps compare equipment across regions — European car specs in kW vs. American in hp, or industrial motors labeled in hp but factory power supply in kW. The different horsepower standards (mechanical, electrical, metric) vary by less than 2%, but precision matters for engineering calculations.
Frequently Asked Questions
Sources & References
Related Calculators
Reviews
No reviews yet. Be the first to share your experience with Power Converter — Watts, Horsepower, BTU/h & More.
Write a Review