About

Power conversion is a critical task in mechanical engineering, automotive performance, and HVAC planning. A mismatch in units - confusing Metric Horsepower with Mechanical Horsepower, for example - can lead to efficiency errors in motor specifications or cooling system designs. This tool provides high-precision bidirectional conversion across both standard and scientific systems. It strictly adheres to international standards for unit definitions, such as the specific definition of the BTU (IT) and the Watt.

Formulas

Conversion relies on linear scaling factors relative to the base SI unit, the Watt.

P_target = P_source × k_sourcek_target

Where k is the conversion factor to Watts. For example, 1 hp = 745.699872 W.

Reference Data

Unit Name	Symbol	Relation to 1 Watt (W)	Common Use
Watt	W	1	SI Standard
Kilowatt	kW	1,000	Home appliances
Horsepower (Mech)	hp(I)	≈ 745.7	US/UK Automotive
Horsepower (Metric)	hp(M)	≈ 735.5	European Auto
BTU per Hour	BTU/h	≈ 0.293	HVAC / AC
Foot-pound/min	ft⋅lb/min	≈ 0.0226	Old Engineering

Frequently Asked Questions

Mechanical HP (Imperial) is approx 745.7 Watts. Metric HP (PS, cv, ch) is approx 735.5 Watts. This 1.4% difference becomes significant in high-performance engine tuning.

12,000 BTU/h is equivalent to 1 "Ton" of refrigeration. This tool handles the direct conversion to Watts or Kilowatts for electrical load estimation.

Yes. While Ergs are CGS units for energy, erg/s is a valid power unit (1 erg/s = 10^-7 W) included in our database.

The Watt is the SI derived unit of power, defined as 1 Joule per second. It serves as the universal bridge between electrical, mechanical, and thermal systems.