Aircon "Tonner" to HP Calculator
A "tonner" is simply a ton of cooling. Enter the tonner rating and get the horsepower class, the BTU figure, and the room size it suits.
"Tonner" is everyday shorthand across the Philippines and Malaysia for an air conditioner's tonnage. A 3 tonner is a 3 ton unit — 36,000 BTU/hr of cooling. The word causes confusion mainly because the same machine is often quoted in horsepower elsewhere in the same shop.
What "Tonner" Actually Means
A tonner is a ton of refrigeration, and one ton is defined as exactly 12,000 BTU/hr — the cooling rate that would melt one short ton of ice in a day. The term has nothing to do with the unit's weight, and nothing to do with how many people it cools.
Because tonnage and horsepower are two separate scales, converting between them never produces round numbers. One tonner works out to 1.33 HP by arithmetic, which retailers round to the 1.5 HP model. The larger the unit, the further the two scales drift apart.
Tonner to HP Conversion Chart
This is the full ladder for the sizes commonly sold. Use the BTU column when comparing against an online listing, since manufacturers publish BTU on virtually every spec sheet.
| Tonner | BTU/hr | Arithmetic HP | Practical HP | Typical use |
|---|---|---|---|---|
| 1 tonner | 12,000 | 1.33 | 1.5 HP | Bedroom, small office |
| 2 tonner | 24,000 | 2.67 | 2.5 HP | Living room, classroom |
| 3 tonner | 36,000 | 4.00 | 4.0 HP | Open-plan floor, small shop |
| 4 tonner | 48,000 | 5.33 | 5.5 HP | Restaurant, clinic |
| 5 tonner | 60,000 | 6.67 | 6.5 HP | Function room, retail unit |
| 6 tonner | 72,000 | 8.00 | 8.0 HP | Light commercial |
At 3 tonner and above the horsepower label starts losing its usefulness — these are commercial machines usually specified in tons or kW, and suppliers rarely badge them in HP at all. If you're quoting a job at this size, work in tons and BTU and leave horsepower out of it.
What Room Size Does Each Tonner Suit?
As a planning figure, allow roughly 500 BTU/hr per square metre for a room with a standard 2.7 m ceiling and moderate sun. On that basis:
| Tonner | BTU/hr | Floor area (standard) | Floor area (hot / sunny) |
|---|---|---|---|
| 1 tonner | 12,000 | Up to 24 m² | Up to 18 m² |
| 2 tonner | 24,000 | Up to 48 m² | Up to 36 m² |
| 3 tonner | 36,000 | Up to 72 m² | Up to 54 m² |
| 5 tonner | 60,000 | Up to 120 m² | Up to 90 m² |
Rooms with west-facing glass, a metal roof, poor insulation or heavy foot traffic need the next size up. Kitchens and server rooms need considerably more again because of the internal heat load. For a calculation that accounts for ceiling height, sun exposure and occupancy, use our aircon HP by room size calculator.
Bigger Is Not Better
It's tempting to buy a larger tonner "to be safe", but an oversized air conditioner cools the air quickly and then shuts off before it has removed enough moisture. The result is a room that feels cold and clammy, plus a compressor that short-cycles — switching on and off repeatedly, which wastes electricity and shortens its life.
An undersized unit has the opposite problem: it runs continuously without reaching the set temperature. Sizing correctly matters more than sizing generously.
Tonner, Ton, TR and HP — All the Same Family
You'll see the same machine described four ways depending on who's writing the listing. "3 tonner", "3 ton", "3 TR" and "36,000 BTU" are identical. Only horsepower is a genuinely different scale, and only because it uses a 9,000 BTU anchor instead of 12,000. Our ton to HP calculator covers the formal tonnage notation, and BTU to HP handles conversions straight from the spec plate.
Frequently Asked Questions
A 3 tonner is 36,000 BTU/hr, which works out to 4 HP. At this size the unit is commercial rather than residential, and suppliers usually quote tons rather than horsepower.
A 1 tonner is 12,000 BTU/hr. The arithmetic gives 1.33 HP, but it is sold as a 1.5 HP unit — the nearest manufactured size.
A 2 tonner is 24,000 BTU/hr — 2.67 HP by arithmetic, sold as a 2.5 HP unit.
Tonner is everyday shorthand for tons of refrigeration, used widely in the Philippines and Malaysia. One tonner equals 12,000 BTU/hr of cooling — nothing to do with the unit's weight.
Yes. A 3 tonner, a 3 ton unit and a 3 TR unit are the same machine at 36,000 BTU/hr. "Tonner" is simply the colloquial form.
A 1 tonner delivers 12,000 BTU/hr, suiting a room of roughly 24 m² with a standard ceiling and moderate sun — closer to 18 m² if it has west-facing windows or a metal roof.
A 5 HP unit is roughly 45,000 BTU/hr, or about 3.75 tons — between a 3 and 4 tonner, and usually quoted as a 4 tonner.