AC Capacity and Room Size Calculator
Enter your room dimensions and environmental factors to calculate the precise cooling capacity required.
swap_horizMeter to Foot Converter
Quickly convert your measurements if you have them in meters.
straighten Room Dimensions
eco Environmental Factors
Required Capacity
assignment Calculation Details
For top floors or rooms with direct sunlight on the roof, it's generally recommended to increase your calculated capacity by 10-15% to compensate for the additional thermal load.
Recommended 1.5 Ton AC Brands
How To Calculate AC Capacity For A Room?
Confused about AC capacity and tonnage for your room? Our AC capacity calculator gives you a quick estimate of the cooling capacity your room needs, in tons and BTU.
To use it, enter your room's width, length and height in feet. Then add the number of people who usually use the room, the highest outdoor temperature in your area, how much sunlight the room gets, the type of furniture, and whether the room stores a lot of papers or books. If you measured in metres, use the Meter to Foot Converter at the top of the tool first.
Getting the size right matters. An AC that is too small runs nonstop and still struggles to cool the room. One that is too big switches on and off too often, which leaves the room cold but humid and wastes power.
Here is the step-by-step method the calculator uses to find the right AC tonnage for your room size:
1. Find the Basic Capacity From Your Room Size
- Multiply the room's width by its length to get the floor area in square feet.
- Match the area to the table below to get the basic capacity.
| Room size | Basic capacity |
|---|---|
| Up to 100 sq ft | 0.8 ton |
| 101 to 150 sq ft | 1 ton |
| 151 to 200 sq ft | 1.5 ton |
| 201 to 250 sq ft | 2 ton |
| 251 to 300 sq ft | 2.5 ton |
- For rooms larger than 300 sq ft, add 0.5 ton for every extra 100 sq ft.
2. Adjust for the Number of People
- Add 0.5 ton for every full group of 5 people who regularly use the room.
- For example, 1 to 4 people add nothing, 5 to 9 people add 0.5 ton, and 10 to 14 people add 1 ton.
3. Add Extra Capacity for Heat
Some rooms take in more heat than others. Add these to the basic capacity where they apply:
- Outdoor temperature above 45°C: Add 0.5 ton.
- Heavy, direct sunlight (for example, a top-floor or terrace flat): Add 0.5 ton.
- Moderate sunlight: Add 0.25 ton.
- Ceiling higher than 12 feet: Add 0.5 ton.
- Metal furniture: Add 0.5 ton.
- Mixed wood and metal furniture: Add 0.25 ton.
- Lots of papers or books in the room: Add 0.5 ton.
4. Round Up to the Nearest AC Size
- Add everything together. The calculator then rounds the total up to the next AC size sold in India: 0.8, 1, 1.5, 2 or 2.5 ton. It never rounds down, so your room always gets enough cooling.
- It also shows the capacity in BTU per hour. One ton equals 12,000 BTU per hour.
- If your room needs more than 2.5 tons, the calculator shows 2.5 tons with a "Consider Upsizing" note. For a room that size, two ACs often work better than one. A technician can help you decide.
Example: A 10 x 12 Feet Bedroom
A 10 ft x 12 ft bedroom has an area of 120 sq ft, so its basic capacity is 1 ton. Two people sleep there, which adds nothing. The room gets moderate sunlight, which adds 0.25 ton, making the total 1.25 tons. The calculator rounds this up to a 1.5 ton AC, or 18,000 BTU per hour.