Tons to BTU/hr
Convert tons of refrigeration (RT) to BTU per hour at the fixed ratio 1 ton = 12,000 BTU/hr.
Interactive
Scale explorer
Drag the slider or click a tier to see where your RT value lands on the equipment scale — with live BTU/hr output.
Fundamentals
What is RT to BTU/hr?
Tons to BTU/hr converts tons of refrigeration to BTU per hour by multiplying the ton value by 12,000. One ton of refrigeration (RT) equals exactly 12,000 BTU/hr. The unit comes from the cooling power needed to melt one short ton (2,000 pounds) of ice in 24 hours. U.S. HVAC contractors size AC units in tons, while equipment specs list BTU/hr — the conversion P(BTU/hr) = P(tons) × 12,000 bridges the two.
A ton of refrigeration is a rate of heat removal equal to 12,000 BTU/hr, or about 3,516.85 watts. It originated in the ice industry — the cooling power needed to freeze one short ton of water at 32°F in 24 hours.
Residential AC typically ranges from 1 to 5 tons. Commercial chillers start at 5–20 tons for small buildings and scale to hundreds of tons for large facilities.
The unit has survived because U.S. HVAC contractors, sales literature, and industry training all use it. International markets prefer kW, which converts through the same base factor.
Formula
RT to BTU/hr formula
Convert a 2-ton home AC unit to BTU/hr. The result, 24,000 BTU/hr, matches the capacity label on the equipment.
How to convert RT to BTU/hr
Three steps complete the conversion:
Find the ton rating
Check the spec sheet, nameplate, or contractor proposal. Typical home units are 1, 1.5, 2, 2.5, 3, 4, or 5 tons.
Multiply by 12,000
Each ton equals 12,000 BTU/hr exactly. No unit conversion error creeps in.
Check against the label
BTU/hr is printed on most AC nameplates. The result should match within rounding.
Applications
When to convert RT to BTU/hr
Real-world scenarios where this conversion shows up in engineering, HVAC, and equipment specification work.
Match contractor tonnage quotes to manufacturer BTU/hr nameplates.
Compare a tons-rated old unit against a new BTU/hr-labeled model.
Read engineering schedules in tons and translate to nameplate BTU/hr.
Convert legacy ton ratings in old building drawings to current BTU/hr specs.
Help new HVAC sales reps see how tons map to BTU/hr across product lines.
Guidance
Tips and common pitfalls
The 12,000 BTU/hr figure is the U.S. short-ton standard. A metric ton of refrigeration is roughly 3,861 kcal/hr (slightly different).
An oversized AC short-cycles, wears compressors, and dehumidifies poorly. Match tons to load, not to 'extra margin'.
Manufacturers sell 1, 1.5, 2, 2.5, 3, 3.5, 4, 5 ton units. Fractional tonnage maps to standard BTU/hr points (18,000, 30,000, 42,000, etc.).
Reference
RT to BTU/hr conversion table
| Tons of refrigeration (RT) | BTU per hour (BTU/hr) |
|---|---|
| 0.5 RT | 6,000 BTU/hr |
| 1 RT | 12,000 BTU/hr |
| 1.5 RT | 18,000 BTU/hr |
| 2 RT | 24,000 BTU/hr |
| 2.5 RT | 30,000 BTU/hr |
| 3 RT | 36,000 BTU/hr |
| 3.5 RT | 42,000 BTU/hr |
| 4 RT | 48,000 BTU/hr |
| 5 RT | 60,000 BTU/hr |
| 7.5 RT | 90,000 BTU/hr |
| 10 RT | 120,000 BTU/hr |
| 15 RT | 180,000 BTU/hr |
| 20 RT | 240,000 BTU/hr |
| 50 RT | 600,000 BTU/hr |
| 100 RT | 1,200,000 BTU/hr |
The ton of refrigeration was defined in the 1870s. Ice companies rated chillers by how much ice they could replace — one ton per day equals 12,000 BTU/hr of continuous cooling.
Questions
Frequently asked
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