BTU Unit Converters
Three constants cover every HVAC conversion you will meet: 1 ton = 12,000 BTU/hr, 1 kW = 3,412 BTU/hr, and 1 W = 3.412 BTU/hr. Each converter below applies one of them, shows a lookup table, and explains where the number comes from.
BTU to Tons
tons = BTU/hr ÷ 12,000
Convert BTU/hr to tons of cooling instantly. 12,000 BTU = 1 ton. Table from 5,000 to 60,000 BTU with the matching AC tonnage, plus what tonnage means.
Tons to BTU
BTU/hr = tons × 12,000
Convert tons of air conditioning to BTU per hour. 1 ton = 12,000 BTU. Table for 1 to 5 ton systems with square footage each size typically covers.
BTU to Watts
W = BTU/hr ÷ 3.412
Convert BTU/hr to watts: 1 BTU/hr = 0.293 W. Instant converter, a table of common AC and heater sizes, and why label watts differ from cooling watts.
Watts to BTU
BTU/hr = W × 3.412
Convert watts to BTU/hr: 1 W = 3.412 BTU/hr, so 1,500 W = 5,118 BTU. Table of common space heater and baseboard wattages and the room each covers.
BTU to kW
kW = BTU/hr ÷ 3,412.14
Convert BTU/hr to kilowatts: 1 kW = 3,412 BTU/hr. Instant converter and a table of AC and heat pump sizes for comparing US and international ratings.
kW to BTU
BTU/hr = kW × 3,412.14
Convert kilowatts to BTU/hr: 1 kW = 3,412 BTU/hr. Instant converter plus a table for common 1 to 25 kW heater, boiler and AC ratings with US equivalents.
Constants used
- 1 ton of refrigeration = 12,000 BTU/hr
- 1 kilowatt = 3,412.14 BTU/hr
- 1 watt = 3.41214 BTU/hr
- 1 BTU = 1,055.06 joules = 0.293071 watt-hours