BTU/hour to Horsepower Converter
Enter a value to instantly convert between power units.
1 BTU/hour = 0.0004 Horsepower (mech)
Key Formulas
Kilowatt → Horsepower (mech)
hp = kW × 1.34102Horsepower (mech) → Kilowatt
kW = hp × 0.7457Watt → Kilowatt
kW = W × 0.001Kilowatt → Watt
W = kW × 1000Formula
hp = BTU/h ÷ 2544.43Mechanical engineers sometimes need to bridge thermal ratings (BTU/h) and mechanical power ratings (hp) when selecting drives for heat pumps, chillers, and HVAC compressors. A 25,000 BTU/h commercial condensing unit requires about 9.8 hp of compressor drive — knowing this helps select the correct motor frame size. The conversion also appears in thermodynamics textbooks where work and heat are shown to be equivalent forms of energy.
Source: NIST SP 811, Table B.8
Last reviewed: · see our methodology
Frequently Asked Questions
Real-World Examples
2,544 BTU/h = exactly 1 hp — the fundamental equivalence point used in thermodynamics and mechanical engineering.
2544 BTU/h = 1 hp
A 12,000 BTU/h (1-ton) AC compressor requires about 4.7 hp of drive — used for motor selection in commercial chiller design.
12000 BTU/h = 4.72 hp
A 25,000 BTU/h rooftop unit compressor = 9.8 hp — helps specify the drive motor when repairing or upgrading commercial HVAC.
25000 BTU/h = 9.83 hp
A 50,000 BTU/h industrial chiller = 19.6 hp of theoretical compressor work — actual motor sizing adds 20–25% for efficiency losses.
50000 BTU/h = 19.65 hp