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, Founder & Markets Trader
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 – 1 ton |
| 110 – 130 sqft | 1 ton |
| 130 – 190 sqft | 1.5 ton |
| 190 – 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.