From watts (W)
- Watts to KilowattsW → kW
- Watts to MegawattsW → MW
- Watts to Mechanical horsepowerW → hp
- Watts to International Table Btu per hourW → Btu_IT/h
Power conversion family
Power unit conversions
Power is the rate of energy transfer or work per unit time and has dimension M L² T⁻³; the coherent SI unit is the watt (W), equal to J/s.
Five named units
Unit and factor reference
| Unit | Symbol | Factor to base | Relationship | Definition and variant |
|---|---|---|---|---|
| watt | W | 1 | defined | The watt is the coherent SI unit of power: 1 W = 1 J/s = 1 kg·m²·s⁻³. The base factor is exactly 1 by the family base-unit choice. |
| kilowatt | kW | 1000 | exact | A kilowatt is the SI decimal multiple formed with kilo: 1 kW = 1000 W. The decimal-prefix relationship is exact. |
| megawatt | MW | 1000000 | exact | A megawatt is the SI decimal multiple formed with mega: 1 MW = 1,000,000 W. The decimal-prefix relationship is exact. |
| mechanical horsepower | hp | 745.699872 | approximate | Mechanical horsepower in this family is 550 international foot-pounds-force per second. With standard gravity, the exact chain gives approximately 745.699871582270 W. Named variant: Mechanical horsepower (550 ft·lbf/s); not metric, electric, boiler, water, or nominal manufacturer horsepower. The preserved baseFactor 745.699872 W is rounded from about 745.699871582270 W, a difference of about 4.18×10⁻⁷ W per hp. |
| International Table Btu per hour | Btu_IT/h | 0.2930710701722222 | approximate | International Table Btu per hour is Btu_IT divided by the fixed 3600-second hour: exactly 1055.05585262/3600 W, a repeating decimal approximately 0.293071070172222 W. Named variant: International Table Btu per hour (Btu_IT/h); not Btu_th/h or an unqualified Btu variant. The source dataset preserves JavaScript's raw evaluated value for 1055.05585262/3600. The exact quotient is repeating; the generator's 15-significant-digit emission is 0.293071070172222 W. |
Every ordered pair
All 20 power calculators
From kilowatts (kW)
- Kilowatts to WattskW → W
- Kilowatts to MegawattskW → MW
- Kilowatts to Mechanical horsepowerkW → hp
- Kilowatts to International Table Btu per hourkW → Btu_IT/h
From megawatts (MW)
- Megawatts to WattsMW → W
- Megawatts to KilowattsMW → kW
- Megawatts to Mechanical horsepowerMW → hp
- Megawatts to International Table Btu per hourMW → Btu_IT/h
From mechanical horsepower (hp)
From international table btu per hour (Btu_IT/h)
- International Table Btu per hour to WattsBtu_IT/h → W
- International Table Btu per hour to KilowattsBtu_IT/h → kW
- International Table Btu per hour to MegawattsBtu_IT/h → MW
- International Table Btu per hour to Mechanical horsepowerBtu_IT/h → hp
Evidence and review status
This family is machine-reviewed-pending-human. Automated checks verify structure, factor parity and source references; they do not constitute human or specialist approval.
Family assumptions and limits
- This family converts non-negative power magnitudes; it does not compute energy use without a duration or model signed import/export.
- Horsepower means mechanical horsepower defined as 550 international foot-pounds-force per second, using standard gravity; metric, electric, boiler, water, and other horsepower variants differ.
- Btu per hour means International Table Btu per hour (Btu_IT/h), not a thermochemical or other Btu variant.
Authoritative references
- The International System of Units (SI), 9th edition, version 4.01; Bureau International des Poids et Mesures; Section 2.3.4, Table 4, p. 133: power/radiant flux use watt W = kg·m²·s⁻³ = J/s; Section 3, Table 7, p. 138 (kilo and mega).; accessed 2026-08-07
- NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology; Entries 'horsepower (550 ft·lbf/s)' = 7.456999 E+02 W and 'British thermal unit_IT per hour' = 2.930711 E-01 W; footnotes 9 and 23 give exact Btu_IT and pound-force relationships.; accessed 2026-08-07
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement; National Institute of Standards and Technology; Page C-9: international foot = 0.3048 m exactly; used with NIST Appendix B.8's pound-force and mechanical-horsepower definition.; accessed 2026-08-07