ToolRoof

Calculators

Air conditioner size calculator by room area

Estimate AC capacity by room area in BTU/h and tons. A 30 m² room gives a preliminary 18000–24000 BTU/h range; check room conditions before buying.

Processed locally

A comparison estimate, not a final purchase size. Extreme heat, insulation, ceiling height and occupants can change the actual need.

m²

5–100 m²

Choose the estimate you want to compare: LG’s broad area range or the separate ENERGY STAR room-AC chart for a ceiling near 2.4 m. Their assumptions differ, so their results can differ. Neither replaces a heat-load calculation.

More options

600–800 BTU/h / m²

For comparison: 18,000 BTU/h = 1.5 tons; 24,000 BTU/h = 2 tons. These describe cooling capacity, not the number of air conditioners.

ReferenceLG — preliminary area estimate
Help and method

We use the 600–800 BTU/h per m² starting range described by LG, not a regional standard or a heat-load calculation. ENERGY STAR adjustments are not added to this separate method.

Methods and reliability

Worked example

An example you can try or adapt to your own values.

Room area
30 m²

Result

18000–24000 BTU/h · 1.5–2 TR