Which AC Size Do I Need? The AC Tonnage Guide for Pakistani Homes

Buying the wrong AC size is the most common — and most expensive — mistake people make. Too small and the room never feels cool; too big (on a non-inverter AC) and it switches on and off constantly. Here is how to get it right.

What does "ton" mean in an AC?

A ton is a measure of cooling capacity, not weight. One ton of air conditioning removes about 12,000 BTU of heat per hour. So a 1.5 ton AC removes about 18,000 BTU per hour and a 2 ton AC about 24,000.

Quick AC tonnage chart

These figures work out to roughly 90–100 BTU per square foot, which suits Pakistani summers far better than the 20–25 BTU rules found on foreign websites. The chart assumes a normal ceiling and a room that is not exposed to harsh afternoon sun. Pakistani conditions often require adjustments.

Adjust for real conditions

• Top floor with a roof above: roofs absorb heat all day. Add roughly 15% capacity.
• West-facing walls or big windows: afternoon sun adds a lot of heat. Add around 10%.
• More than two people regularly in the room: add about 600 BTU per extra person.
• Open kitchen: cooking heat can add 4,000 BTU or more.
• High ceilings (12 ft or more): more air to cool — add around 10%.

The easiest way: use our free AC tonnage calculator. It applies these adjustments and shows matching ACs in stock.

Worked example

Take a 12 × 14 ft bedroom (168 sq ft). In hot Pakistani conditions a practical starting point is about 90 BTU per square foot, so the room needs roughly 15,000 BTU — about 1.3 ton. A 1.5 ton AC is the right choice. Now put the same room on a top floor with afternoon sun: add about 15% for the roof and 12% for the sun and the load rises to roughly 19,500 BTU — about 1.6 ton. Here a 2 ton AC (or at least a strong 1.5 ton inverter, accepting that it will work hard on the hottest afternoons) is the safer choice.

Does a bigger AC cool faster?

Yes, but with a conventional AC, an oversized unit cools the air quickly and switches off before removing humidity, leaving the room cold but clammy. Inverter ACs handle slight oversizing far better because they slow down once the room reaches the set temperature. If you are between two sizes and the room gets direct sun, choose the bigger inverter model.

Inverter or conventional?

For rooms used more than a few hours a day, inverter is almost always the better buy. See inverter vs non-inverter AC for the full comparison, or estimate your savings with the inverter savings calculator.

Ready to choose?

Browse our Dawlance inverter ACs in 1, 1.5 and 2 ton — genuine units with official warranty and cash on delivery. Our team can also help you confirm the size on WhatsApp if you send the room measurements.