Convert Horsepower to Tons of refrigeration
1 horsepower is 0.21 TR. One horsepower is exactly 0.21203613147 tons of refrigeration.
One horsepower is 0.21203613 tons of refrigeration. To convert horsepower to tons of refrigeration, multiply by 0.21203613; to go the other way, divide by 0.21203613 or multiply by 4.7161773. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Special Publication 811. Mechanical horsepower: exactly 550 foot-pounds of work every second, the figure James Watt settled on to sell engines against pit ponies.
Factor checked against the defining standard · How we check
- Horsepower × 0.21203613
1 * 0.21203610.212 TR
1 horsepower in every power unit
| Unit | Value | Exact factor |
|---|---|---|
| horsepower (as entered) | 1 hp | — |
| metric horsepower | 1.013869665 PS | × 1.01386966542 |
| watts | 745.6998716 W | × 745.699871582 |
| kilowatts | 0.7456998716 kW | × 0.745699871582 |
| milliwatts | 745,699.8716 mW | × 745,699.871582 |
| megawatts | 0.0007456998716 MW | × 0.000745699871582 |
| tons of refrigeration | 0.2120361315 TR | × 0.21203613147 |
| BTU per hour | 2,544.433578 BTU/h | × 2,544.43357764 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert horsepower to tons of refrigeration? The converter and the working
- 1.Take the measurement in horsepower.
- 2.Multiply by 0.21203613 — that is how many tons of refrigeration fit in one horsepower.
- 3.To go back the other way, divide by 0.21203613, or multiply by 4.7161773.
Worked example: 25 horsepower to tons of refrigeration
- Formula
- hp × 0.21203613 = TR
- Arithmetic
- 25 × 0.21203613 = 5.3 TR
- Answer
- 25 hp = 5.3 TR
The factor is rounded for display; the figure above is computed from the full value.
Horsepower to tons of refrigeration conversion table
| Horsepower | Tons of refrigeration |
|---|---|
| 1 hp | 0.21 TR |
| 2 hp | 0.42 TR |
| 3 hp | 0.64 TR |
| 4 hp | 0.85 TR |
| 5 hp | 1.06 TR |
| 6 hp | 1.27 TR |
| 7 hp | 1.48 TR |
| 8 hp | 1.7 TR |
| 9 hp | 1.91 TR |
| 10 hp | 2.12 TR |
| 12 hp | 2.54 TR |
| 15 hp | 3.18 TR |
| 20 hp | 4.24 TR |
| 25 hp | 5.3 TR |
| 50 hp | 10.6 TR |
| 100 hp | 21.2 TR |
| 200 hp | 42.41 TR |
| 300 hp | 63.61 TR |
| 500 hp | 106.02 TR |
| 1000 hp | 212.04 TR |
| 2000 hp | 424.07 TR |
| 5000 hp | 1,060.18 TR |
| 10000 hp | 2,120.36 TR |
What is a horsepower?
Mechanical horsepower: exactly 550 foot-pounds of work every second, the figure James Watt settled on to sell engines against pit ponies. US vehicle and motor ratings use it.
What is a ton of refrigeration?
Exactly 12,000 BTU an hour — the rate at which a short ton of ice melts over a day, which is what air conditioning was measured against before it was made electrically. A three-ton domestic unit is 36,000 BTU/h, or 10.5 kW.
How many tons of refrigeration are in a horsepower?
One horsepower is 0.21203613 tons of refrigeration. Going the other way, one ton of refrigeration is 4.7161773 horsepower. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every power unit here
The whole group — 8 units with their symbols and the size of each one in watts — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a horsepower.
Source: NIST Special Publication 811 — mechanical horsepower is 550 ft·lbf/s exactly
Cite this page
- APA
- Rule Calculator. (2026). Convert Horsepower to tons of refrigeration. Rule Calculator. https://rulecalculators.com/convert/horsepower-to-ton-of-refrigeration
- MLA
- "Convert Horsepower to tons of refrigeration." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/horsepower-to-ton-of-refrigeration.
- Chicago
- Rule Calculator. "Convert Horsepower to tons of refrigeration." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/horsepower-to-ton-of-refrigeration.
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Questions people actually ask
- How many tons of refrigeration are in a horsepower?
- 0.21203613. Exactly 12,000 BTU an hour — the rate at which a short ton of ice melts over a day, which is what air conditioning was measured against before it was made electrically. A three-ton domestic unit is 36,000 BTU/h, or 10.5 kW.
- How do I convert tons of refrigeration back to horsepower?
- Divide by 0.21203613, or multiply by 4.7161773 — they are the same operation.
Other power conversions
Tons of refrigeration to horsepower — the same conversion the other way.