AC size guide
18x20 Room AC Size
Most 18x20 ft (360 sq ft) rooms need a 3 x 2 ton AC. A shaded room can use 2 x 2 ton.
Size for your type of room
| Room type | Cooling load | AC size |
|---|---|---|
| Shaded room, lower or middle floor | 43,864 BTU/h | 2 x 2 ton |
| Normal sun, middle floor | 48,184 BTU/h | 3 x 2 ton |
| West-facing or top floor | 57,472 BTU/h | 3 x 2 ton |
One split AC is not enough here
For this size, use two or more split ACs, cassette ACs, or a VRF system. Cooling comes out more even and you can switch off part of the room.
Check your exact room
The calculator is filled with this room size. Add ceiling height, sun, floor and people for your exact answer.
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Live estimate
360 sq ft · approx 2 × 2.0 Ton ACs
Calculate for cost & models
Fine-tune: sunlight, floor, ceiling height, occupancy▾
What changes the size
- Afternoon sun on a west wall can add 10 to 15%.
- A top floor under a concrete roof adds about 10%.
- Each extra person adds about 600 BTU/h.
- A ceiling above 10 ft adds about 10% per foot.
- A kitchen or many electronics add 1,000 to 3,400 BTU/h.
Commercial projects team (VRF, offices, shops)
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Common questions
›How many ton AC for a 18x20 room?
Most 18x20 ft (360 sq ft) rooms need a 3 x 2 ton AC. A shaded room can use 2 x 2 ton.
›18 by 20 room me kitne ton ka AC lagega?
Normal dhoop aur beech ki manzil par 3 x 2 ton ka AC. Chhaon wale room me 2 x 2 ton kaafi hai.
›Is a bigger AC better?
No. An oversized AC switches on and off often, removes less humidity and wastes power. Buy the right size.