BTU per hour (BTU/h)
1 BTU per hour = 0.29307107 watts
What is BTU per hour?
BTU per hour is a unit of power used to measure the heating or cooling capacity of HVAC equipment. It is the standard rating system for air conditioners, furnaces, and heat pumps in the United States.
Notes: HVAC rating
Real-world uses
BTU per hour is the standard power unit for rating furnaces, air conditioners, heat pumps, and boilers in the United States. A residential central air conditioner might be rated at 24,000–60,000 BTU/h. In casual use, the "/h" is often dropped, so "12,000 BTU air conditioner" actually means 12,000 BTU/h.
History
BTU/h became the standard power unit for the US HVAC industry during the post-World War II residential building boom, as central air conditioning and forced-air heating became widespread. Industry standards bodies such as AHRI codified BTU/h ratings for equipment comparison.
Common mistakes
Dropping the "/h": confusing BTU (energy) with BTU/h (power) is extremely common in HVAC contexts. A unit absorbing 12,000 BTU in one hour is operating at 12,000 BTU/h of capacity. Also, 1 ton of refrigeration = 12,000 BTU/h, which can cause confusion in capacity comparisons.
When is this conversion used?
Converting between BTU per hour and watt is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.
How to convert BTU per hour to watt
To convert BTU per hour to watt, multiply the value by 0.29307107.
Conversion formula (from base unit)
x * 0.29307107
Measurement standards
The watt is the SI derived unit of power, defined as one joule per second (kg·m²/s³). Horsepower remains in widespread informal use, particularly in the automotive industry, but has no single universal definition across regions.
Did you know?
The human body at rest produces about 80 watts of power — roughly enough to keep an incandescent light bulb glowing. During intense exercise, a trained cyclist can sustain over 400 watts, and elite sprinters briefly exceed 2,000 watts.
| BTUs per hour | watts |
|---|---|
| 0.1 | 0.02930711 |
| 0.5 | 0.14653553 |
| 1 | 0.29307107 |
| 2 | 0.58614214 |
| 5 | 1.46535535 |
| 10 | 2.9307107 |
| 25 | 7.32677675 |
| 50 | 14.6535535 |
| 100 | 29.307107 |
| 250 | 73.2677675 |
| 500 | 146.535535 |
| 1,000 | 293.07107 |
Common values
| BTUs per hour | watts | |
|---|---|---|
| LED light bulb | 34.12141635 BTUs per hour | 10 watts |
| Desktop computer | 1,023.64249054 BTUs per hour | 300 watts |
| Microwave oven | 3,412.14163513 BTUs per hour | 1,000 watts |
| Small car engine | 255,910.62263498 BTUs per hour | 75,000 watts |
| Wind turbine (large) | 10,236,424.90539923 BTUs per hour | 3,000,000 watts |
Full BTU per hour conversion table
| Unit | Value | Factor |
|---|---|---|
| watt | 1 BTU/h = 0.29307107 W | × 0.29307107 |
| kilowatt | 1 BTU/h = 0.00029307 kW | × 0.00029307 |
| horsepower (mechanical) | 1 BTU/h = 0.00039301 hp | × 0.00039301 |
| megawatt | 1 BTU/h = 2.930711e-07 MW | × 2.930711e-07 |
| gigawatt | 1 BTU/h = 2.930711e-10 GW | × 2.930711e-10 |
| milliwatt | 1 BTU/h = 293.07107 mW | × 293.07107 |
| microwatt | 1 BTU/h = 293,071.07 µW | × 293,071.07 |
| kilocalorie per hour | 1 BTU/h = 0.25199576 kcal/h | × 0.25199576 |
| ton of refrigeration | 1 BTU/h = 0.00008333 TR | × 0.00008333 |