Aircon BTU Calculator

Enter your room area in square feet for an estimated BTU and aircon size in HP. Rough guidance only, not an engineering load calculation.

This result is an estimate only. Check with your bank or the relevant authority before making decisions.

How it is calculated

BTU = area (square feet) × 60
If the room gets strong sun or is on the top floor: × 1.15
If the ceiling is higher than 10 feet: × 1.10
Pick the smallest size that is enough: 1.0 HP (9,000 BTU/h), 1.5 HP (12,000), 2.0 HP (18,000) or 2.5 HP (24,000)

If the need is above 24,000 BTU/h, the calculator suggests several units. This is a rule of thumb, not an engineering load calculation.

Worked example

120 square feet: 120 × 60 = 7,200 BTU/h → 1.0 HP
200 square feet: 200 × 60 = 12,000 BTU/h → 1.5 HP
200 square feet with strong sun: 12,000 × 1.15 = 13,800 BTU/h → 2.0 HP
300 square feet: 300 × 60 = 18,000 BTU/h → 2.0 HP

Why your number may differ

The 60 BTU per square foot rule is a rough estimate. Insulation, window size and direction, the number of people, heat-producing appliances and cooking all affect what you really need, and this calculator does not include them. BTU ratings per HP also vary a little between brands and models. Ask a licensed installer before you buy.

Frequently asked questions

How many BTU per HP?

On the market, 1.0 HP is usually about 9,000 BTU/h, 1.5 HP about 12,000, 2.0 HP about 18,000 and 2.5 HP about 24,000.

Why 60 BTU per square foot?

It is a common rule of thumb for hot climates. Real conditions such as insulation, windows and the number of people can change what you need.

Should I rely on this number alone?

No. This is guidance only. Ask a licensed installer before you buy.