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Unit converters · Common

Power converter

Convert power between watts, horsepower, BTU/hour, calories/second, and dozens more units.

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How it works

Two steps, no account

1

Pick your units

SI watts, mechanical horsepower variants, HVAC units (BTU/h, tons of refrigeration), or energy-per-time.

2

Enter a value

The result updates instantly as you type, or as soon as you change either unit.

FAQ

Common questions

Is my data sent anywhere?
No. The conversion runs entirely in your browser — nothing is transmitted, logged, or stored.
Why are there so many horsepower units?
"Horsepower" was standardized differently across industries and countries — mechanical, metric, boiler, and electric horsepower are all slightly different values. Pick the variant that matches your source to avoid a small but real discrepancy.
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Power Converter

Convert between different units of power, from scientific calculations to automotive and heating/cooling applications.

How to Use

1. Enter Value

Input the power value.

2. Select Units

  • From: Current unit (e.g., Horsepower).
  • To: Target unit (e.g., Kilowatt).

3. Get Result

View the accurate conversion instantly.

Common Units Explained

  • Watt (W): The standard SI unit of power.
  • Kilowatt (kW): 1,000 Watts. Common for electricity billing and engine power.
  • Horsepower (hp):
    • Mechanical (Imperial): ~745.7 Watts. Used in the US/UK for engines.
    • Metric (PS): ~735.5 Watts. Used in Europe/Asia.
    • Electric: 746 Watts exactly.
  • BTU/hour: Common in HVAC (heating and cooling) systems.

Use Cases

  • Cars: Convert engine specs from hp to kW.
  • Appliances: Check power consumption (W to kW).
  • AC/Heating: Convert BTU ratings to Watts to understand energy usage.

Technical Details

This tool supports over 50 power units, including:

  • Scientific units (erg/s, J/s)
  • Industrial units (ton of refrigeration)
  • various forms of horsepower (boiler, electric, water)

Conversion factors are precise to significant digits to ensure accuracy for engineering needs.