Convert BTU per Hour to Mechanical Horsepower (BTU/h → hp)

Converting BTU per hour to mechanical horsepower is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in BTU per hour

   Start with the number of BTU per hour (BTU/h) you want to convert.
2. 2
   Multiply by 0.000393

   The conversion factor from BTU/h to hp is 0.000393. Multiply your value by this number.
3. 3
   Read the result in mechanical horsepower

   The result is your value in mechanical horsepower (hp).

Multiply the value in BTU per hour by 0.000393. For the reverse direction, multiply by 2,544.4336.

• ✓1 BTU/h = 0.293 W; 3412 BTU/h = 1 kW.
• ✓12,000 BTU/h = 1 ton of refrigeration.
• ✓Tons of AC rating: divide BTU/h by 12,000.

• ✗Confusing BTU (energy) with BTU/h (power) — same abbreviation in ads.
• ✗Mixing tons of AC and tons of weight — different concepts.
• ✗Using BTU/h for non-HVAC contexts.

What is the BTU per Hour?

BTU per hour (BTU/h or BTUh) is the standard rating for American heating, air-conditioning, and refrigeration system capacity. A window air conditioner is typically 5,000–12,000 BTU/h, central residential AC ranges 24,000–60,000 BTU/h, and commercial chillers reach 100,000–1,000,000+ BTU/h. The unit's persistence in HVAC reflects American engineering tradition: it directly links cooling/heating capacity to the BTU energy unit familiar in gas-fired equipment. 12,000 BTU/h equals 'one ton of refrigeration' (a unit derived from the heat needed to melt 1 ton of ice in 24 hours), so AC sizes are sometimes given in 'tons' (a 3-ton AC = 36,000 BTU/h). BTU/h relates to the watt (1 W ≈ 3.412 BTU/h), the kilowatt (1 kW ≈ 3,412 BTU/h), and the ton of refrigeration (12,000 BTU/h = 1 ton). Outside the US, kW is dominant for HVAC capacity.

• US air conditioners and heat pumps
• US furnace and boiler ratings
• Some industrial heat-exchanger specs

What is the Mechanical Horsepower?

Horsepower (hp) equals exactly 745.6998715822702 watts (mechanical horsepower) and is the American and British unit for car engines, motorcycles, motorboats, and traditional mechanical power ratings. James Watt invented the unit in the 1780s to market his steam engines: he calculated that a brewery horse could continuously turn a mill wheel at 33,000 ft·lb per minute, which became 1 horsepower. American cars typically range from 150 hp (economy) to 700 hp (sports cars), pickup trucks 250–500 hp, and large diesel trucks 400–600 hp. Outside the US, the metric horsepower (PS or CV, equal to 735.5 W — about 1.4% smaller than mechanical hp) is sometimes used. Horsepower relates to the watt (1 hp ≈ 745.7 W), the kilowatt (1 hp ≈ 0.746 kW), and the metric horsepower (1 hp ≈ 1.014 PS). Despite SI's preference for the watt, horsepower remains entrenched in automotive marketing.

• US car and motorcycle engine ratings
• Lawn mower and small engine specs
• US pump and compressor ratings