HP to Ton Converter
Convert horsepower to tons of refrigeration — both the exact mechanical conversion and the aircon market convention.
"HP to ton" means two different things depending on context. This converter gives both: the exact thermodynamic conversion between mechanical horsepower and tons of refrigeration, and the aircon-market convention used to label room air conditioners.
HP to Ton Formulas
Which Conversion Should You Use?
- Comparing an aircon rated in HP with one rated in tons (e.g. Malaysia vs. India spec sheets) → use the aircon convention: a 1.5 ton unit ≈ 2 aircon HP.
- Engineering work — compressor shaft power, chiller COP, motor sizing → use the exact conversion: a 10 ton chiller removes heat at a rate equal to 47.2 HP (its compressor motor draws far less, because refrigeration moves heat rather than converting work directly).
The two differ by a factor of ~3.5 because they measure different things: the exact figure equates power, while the aircon label compares cooling capacity against the rough electrical draw of old 1 HP compressors.
How to Use This Calculator
- Enter the horsepower figure.
- Read both results — the exact refrigeration tons and the aircon-label tons — and pick the one matching your context above.
HP to Tons Conversion Table
| HP | Exact tons (×0.2121) | Aircon-label tons (×0.75) |
|---|---|---|
| 1 | 0.21 | 0.75 |
| 1.5 | 0.32 | 1.13 |
| 2 | 0.42 | 1.50 |
| 3 | 0.64 | 2.25 |
| 5 | 1.06 | 3.75 |
| 10 | 2.12 | 7.50 |
| 20 | 4.24 | 15.0 |
Worked Example
Frequently Asked Questions
Exactly: 1 mechanical HP = 0.212 ton of refrigeration. In aircon labeling: 1 AC HP ≈ 0.75 ton. Use the aircon figure when comparing air conditioner spec sheets.
Exactly: 1 ton of refrigeration = 4.72 mechanical HP. In aircon labeling: 1 ton ≈ 1.33 AC HP, which is why a 1.5 ton unit is sold as a "2 HP" aircon.
The exact figure converts power to power. The aircon figure is a marketing label comparing cooling capacity to the electrical draw of vintage compressors. They differ by roughly 3.5×, so always match the convention to the context.
About 1.5 tons (18,000 BTU/hr). A 2.5 HP unit is roughly 1.9 tons, and a 1 HP unit is 0.75 ton.