BTU per hour (BTU/h)

Definition

British thermal units per hour, about 0.293 watts — the standard rating for heating and cooling.

History

BTU per hour measures the rate of heat transfer, pairing the British thermal unit with the hour. One BTU per hour is about 0.293 watts.

Where it is used

BTU per hour is the standard rating for air conditioners, heaters and furnaces, especially in the US, where a window unit might be 5,000 to 12,000 BTU/h.

Typical uses include air conditioner and heater ratings, HVAC sizing.

Conversion pages

These pages convert BTU per hour to or from another unit in power.

No conversion pages use this unit yet.

Other Power units

• Kilowatt (kW)
• Horsepower (hp)
• Watt (W)
• Megawatt (MW)
• Metric horsepower (PS)

Sources

• NIST SP 811 NIST SP 811, App. B (power). Mechanical hp = 550 ft·lbf/s ≈ 745.70 W; metric hp (PS) = 75 kgf·m/s = 735.49875 W · Dataset reviewed Nov 11, 2026