Tons of refrigeration and BTU per hour
A ton of refrigeration is 12,000 BTU per hour, about 3,517 watts: the cooling from melting one short ton of ice per day. Central air conditioners, chillers and heat pumps in North America are sized in tons.
One BTU per hour is about 0.293 watts. Air conditioners, heaters and furnaces in the US are sized in BTU/h, often written just "BTU".
Worked example
Convert 3 TR: 3 × 12,000 = 36,000, so 3 tons of refrigeration is 36,000 BTU per hour. Likewise 2 TR = 24,000 BTU/h.
Estimating in your head
The factor is a short exact number, so mental math needs no rounding: multiply by 12,000.
Going the other way
To convert BTU per hour to tons of refrigeration, divide by 12,000 (or multiply by 0.0000833333333333). The swap button between the boxes opens that page.
How this works
BTU/h = TR × 12,000
1 TR = ≈ 3,516.852842 W and 1 BTU/h = ≈ 0.2930710702 W, both by definition, so the factor is their ratio: 12,000 exactly. Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.
Frequently asked
How many BTU per hour are in a ton of refrigeration?
1 ton of refrigeration = 12,000 BTU per hour, exactly. The value follows from the unit definitions, so it never changes.
How do I convert tons of refrigeration to BTU per hour?
Multiply by 12,000. For example, 2 TR × 12,000 = 24,000 BTU/h.
What is 10 TR in BTU per hour?
10 TR = 120,000 BTU/h. The table next to the converter lists more common values.
Is the result rounded?
Only on screen. The page computes with the exact definitions and removes floating-point noise past 15 significant digits; pick 3 to 12 significant figures, or use Copy result for the full value.
Sources
- NIST SP 811 Appendix B.8 — Factors for units listed alphabetically
- NIST SP 811 Appendix B.9 — Factors for units listed by kind of quantity
- Wikipedia — Horsepower
Reviewed Oct 17, 2026 · test vectors fixtures/units/power/refrigeration-tons-to-btu-per-hour/