Home & Electrical

AC Tonnage Calculator: What Size AC for My Room?

Free tool · Updated October 2, 2026 · By CouponTalk

Your result

Enter your measurements to see your result.

Quick answer

For Indian summers, a rough guide is 1 ton for rooms up to 120 sq ft, 1.5 ton for 120–180 sq ft and 2 ton for 180–250 sq ft. Add capacity for top-floor or west-facing rooms, high ceilings, more than two people or a hot city. A 150 sq ft bedroom with a normal ceiling needs a 1.5 ton AC.

How to use this calculator

Measure the room length and width in feet.
Measure the ceiling height.
Choose the sun exposure and enter how many people usually use the room.

Reference table

AC size by room area (10 ft ceiling, Indian summer)
Room size	Normal room	Sunny / top floor
Up to 90 sq ft	0.75 ton	1 ton
90–120 sq ft	1 ton	1.5 ton
120–180 sq ft	1.5 ton	2 ton
180–250 sq ft	2 ton	2.5 ton
250–320 sq ft	2.5 ton	3 ton

These are typical figures for Indian homes. Check the product spec sheet, and ask an electrician or installer before you buy or fit anything.

Frequently asked questions

Is a 1.5 ton AC enough for 150 sq ft?

Yes, for a standard 10 ft ceiling and a normal room, 1.5 ton is right for 150 sq ft. Choose 2 ton if it is a top-floor or very sunny room.

Is a 1 ton AC enough for a 12x10 room?

A 120 sq ft room on a middle floor is fine with 1 ton. On a top floor or in a hot city such as Delhi or Nagpur, 1.5 ton cools faster.

Does a bigger AC use more electricity?

A larger AC draws more power, but an undersized AC runs at full power all the time. With an inverter AC, slightly oversized is usually more efficient than undersized.