When shopping for air conditioners, you'll see capacity measured in both BTU and tons. Understanding tonnage helps you compare units and choose the right size.
What is a Ton of Cooling?
A "ton" of air conditioning doesn't refer to weight. It's a measurement of cooling capacity based on how much heat is needed to melt one ton (2,000 lbs) of ice in 24 hours.
1 Ton = 12,000 BTU/hour
Common Tonnage Sizes
- 0.75 Ton (9,000 BTU): Small bedrooms, 100-150 sq ft
- 1 Ton (12,000 BTU): Bedrooms, small offices, 150-250 sq ft
- 1.5 Ton (18,000 BTU): Living rooms, 250-400 sq ft
- 2 Ton (24,000 BTU): Large rooms, 400-550 sq ft
- 2.5 Ton (30,000 BTU): Very large spaces, 550-700 sq ft
BTU to Tonnage Conversion
To convert BTU to tons: divide by 12,000
To convert tons to BTU: multiply by 12,000
Example: 18,000 BTU รท 12,000 = 1.5 Tons
Why Sizing Matters
- Undersized: AC runs constantly, never reaches set temperature, high bills
- Oversized: Short cycles, poor dehumidification, wasted energy
Calculate Your Needs
Use our Tonnage Converter for quick conversions, and our BTU Calculator to find the right size for your room.