Power Converter
Milliwatt
mW
Watt
W
Kilowatt
kW
Megawatt
MW
Gigawatt
GW
Terawatt
TW
Horsepower (mechanical)
hp
Horsepower (electric)
hp (elec)
Horsepower (metric) / PS
PS
Horsepower (boiler)
hp (boil)
BTU per Hour
BTU/h
BTU per Minute
BTU/min
BTU per Second
BTU/s
Kilocalorie per Hour
kcal/h
Ton of Refrigeration
RT
Foot-pound per Second
ft·lbf/s
Foot-pound per Minute
ft·lbf/min
Erg per Second
erg/s
Hover any row to copy the value or use it as the new input.
Privacy First: Your files are processed securely. Whenever possible, processing happens in your browser and files are never stored on our servers.
A comprehensive power converter covering 18 units across four groups - all results shown simultaneously. SI / Metric includes milliwatt, watt, kilowatt, megawatt, gigawatt, and terawatt - the units used in electrical engineering, utility grids, and scientific calculations. Horsepower covers the four major standards: mechanical (550 ft·lbf/s = 745.7 W), electric (746 W, US/NEMA), metric / PS (75 kgf·m/s = 735.5 W), and boiler horsepower (≈ 9,809.5 W). Thermal / HVAC covers BTU per hour, BTU per minute, BTU per second, kilocalorie per hour, and ton of refrigeration (12,000 BTU/h = 3.517 kW) - the units used in air conditioning, furnaces, and heat exchangers. Mechanical / CGS covers foot-pound per second, foot-pound per minute, and erg per second. Type a value, pick a unit, and every other unit updates instantly. Click any result row to reverse the conversion. Adjustable significant figures and scientific notation toggle included. 100% browser-based - your data never leaves your device.
How to Use
- 1Type a power value in the input field
- 2Select your starting unit from the From dropdown - choose from SI / Metric, Horsepower, Thermal / HVAC, or Mechanical / CGS
- 3Select your target unit from the To dropdown - the result appears instantly
- 4All 18 conversions appear simultaneously, grouped by system
- 5Hover any result row to reveal the copy (📋) and use-as-input (⇅) buttons
- 6Click the copy icon to copy a value to your clipboard
- 7Click ⇅ on any row to use that unit and value as the new input for instant reverse conversion
- 8Use the ⇄ button between From and To to swap both units while updating the value
- 9Adjust 'Sig. figures' to control result precision (3 to 12 significant digits)
- 10Toggle 'Sci notation' for very large or small values (e.g. terawatt ↔ milliwatt)
- 11Collapse a group by clicking its header to reduce clutter when you only need one unit system
- 12Open 'Common conversions' at the bottom for a quick-reference table of key power equivalents
Features
- 18 power units across 4 unit groups
- SI / Metric: milliwatt, watt, kilowatt, megawatt, gigawatt, terawatt
- Horsepower: mechanical (745.7 W), electric (746 W), metric / PS (735.5 W), boiler (9,809.5 W)
- Thermal / HVAC: BTU/h, BTU/min, BTU/s, kilocalorie per hour, ton of refrigeration
- Mechanical / CGS: foot-pound per second, foot-pound per minute, erg per second
- All 18 conversions shown simultaneously - no need to select a single target unit
- Click any result row to use it as the new input for instant reverse conversion
- Adjustable significant figures: 3, 4, 5, 6, 8, 10, or 12 digits
- Toggleable scientific notation for extreme ranges (mW ↔ TW)
- Collapsible unit groups to reduce visual clutter
- One-click copy to clipboard for any converted value
- 12-entry quick-reference table for common power conversions (kW, hp, BTU/h, RT, etc.)
- Exact constants: 1 hp (mech) = 745.69987158 W, 1 hp (metric) = 735.49875 W, 1 RT = 3,516.85 W
- 100% browser-based - no server, no data upload
Frequently Asked Questions
Community Feedback
Like
Total Rating
No ratings yetReviews
No reviews yet. Be the first!
Rate & Review
Was this tool helpful?
Rate this tool:
Write a Review