Room area is a starting point for AC sizing
Two rooms with the same floor area can have different cooling needs. Sunny glass and a high ceiling are not equivalent to a shaded, insulated room. Treat area as a first estimate, not a complete purchasing decision.
Read the capacity unit
BTU/h measures heat removed per hour, not electrical input or a count of machines. ENERGY STAR’s room-area chart assumes an 8 ft ceiling. Oversizing is not automatically better: rapid cooling may leave insufficient time for moisture removal.
References: ENERGY STAR
Know what changes the load
Sunlight, occupants and cooking add loads. Very hot climates, glass façades, insulation and high ceilings need a building-specific assessment. An arbitrary area multiplier is not a verified local standard.
Preliminary range by area
A 5 × 6 m room has 30 m². Multiplying by LG’s preliminary 600–800 range gives 18000–24000 BTU/h, or 1.5–2 cooling tons. This is a comparison range, not a promise that 24000 will suffice in every climate. Do not add the following chart’s adjustments to it: different assumptions explain different results. Confirm actual equipment capacity and room load with an installer before buying.
References: LG — preliminary area estimate
ENERGY STAR chart — 2.4 m ceiling
A 5 × 6 m room has 30 m², about 323 ft². It lies in the 300–350 ft² band, giving a base reference of 8000 BTU/h. This is a chart example, not a universal equipment recommendation.
For a very sunny room with 4 people, the example becomes 8000 × 1.10 + 2 × 600 = 10000 BTU/h. Only the two people beyond the baseline are added.
Compare that output with equipment specifications, then confirm the actual room load. A running-cost calculation needs electrical input, operating hours and the tariff; cooling BTU/h alone is not the electricity bill.
References: ENERGY STAR