AC Tonnage Calculator
Find the right air conditioner size for your room based on area, sun exposure, height and occupancy.
Built & reviewed by Ankit Madia
AC Tonnage Calculator
Choosing the right air conditioner size matters more than most buyers realise. Too small and the AC runs all day without cooling the room; too large and it short-cycles, leaves the air humid and wastes electricity. This calculator estimates the cooling load for your room and recommends a standard AC size.
What Does One Ton Mean?
A ton of air conditioning is a unit of cooling capacity, not weight. One ton equals 12,000 BTU per hour, the heat needed to melt one ton of ice in 24 hours. So a 1.5 ton AC removes 18,000 BTU of heat per hour from the room.
Quick Sizing Guide
| Room Area | Typical AC Size |
|---|---|
| Up to 110 sqft | 0.8 to 1 ton |
| 110 to 130 sqft | 1 ton |
| 130 to 190 sqft | 1.5 ton |
| 190 to 250 sqft | 2 ton |
| Above 250 sqft | 2 ton + second unit |
What Raises the Cooling Load
- Sun and top floor: direct sun and roof heat can add 15 to 30% to the load.
- Ceiling height: above 10 feet there is more air volume to cool.
- People: each person adds body heat; crowded rooms need more capacity.
- Appliances: kitchens, servers and many electronics all add heat.
- Climate: hotter cities like Delhi, Nagpur and Ahmedabad need more cooling than coastal or hill towns.
A Note on Accuracy
This tool gives a practical estimate suitable for choosing a home AC. For large halls, glass-heavy offices or commercial spaces, get a proper heat-load survey from an HVAC engineer, which also accounts for wall insulation, glazing, fresh-air requirements and equipment loads.