BTU / AC Sizing Calculator
Enter room area for the cooling capacity (BTU) and Korean AC 'pyeong type', with ceiling, sun, occupant, and kitchen adjustments.
Recommended capacity
Korean type 8.3pyeong · Power 3.52 kW
- Base load
- 12,000 BTU
- Adjusted
- 12,000 BTU
Based on area × 600 BTU/m² plus ceiling/sun/occupant/kitchen adjustments. Also converts to Korean AC 'pyeong type' (1 pyeong ≈ 1,440 BTU). ±20% by insulation and windows.
What this tool does
The BTU / AC sizing calculator computes the cooling capacity (BTU) and Korean AC 'pyeong type' from room area. It adjusts for ceiling height, sun exposure, occupants, and kitchen, and converts to kW — helping you avoid choosing an AC that's too small or too large.
Who uses this
- Confirm AC capacity before buying
- Pick the right 'pyeong type' by room area
- Compare living room, bedroom, kitchen capacity
- Adjust for sunny or crowded spaces
- Convert BTU ↔ pyeong type
How to use
- 1Enter room area (m²) and ceiling height.
- 2Select sun exposure (low/normal/high) and occupants. More sun/people means more capacity.
- 3Check kitchen if applicable (cooking heat). See recommended BTU, Korean pyeong type, and kW.
BTU sizing formula
Base cooling = area (m²) × 600 BTU/m² Adjustments: Ceiling over 2.7m scales proportionally Sun high ×1.1, low ×0.9 Occupants over 2: +600 BTU each Kitchen +4,000 BTU Korean pyeong type: BTU / 1,440 (1 pyeong ≈ 1,440 BTU) kW: BTU × 0.000293
Real examples
Example 1: 20m² bedroom (normal)
20 × 600 = 12,000 BTU ≈ 8.3 pyeong type. Suitable for a standard bedroom wall/stand AC.
Example 2: 30m² living room, high sun, 4 people
30 × 600 × 1.1 + occupant adjustment = ~21,000 BTU ≈ 14.6 pyeong type. Large rooms scale up with sun and people.
Example 3: Space with kitchen
Cooking heat adds +4,000 BTU. Same area, but kitchens need more capacity.
Frequently asked questions
What is BTU?+
British Thermal Unit, a heating/cooling capacity unit — the heat removable (cooling) or supplied (heating) per hour. Higher means more powerful; Korea also labels it as 'pyeong type'.
Is bigger always better?+
No. An oversized unit reaches the set temperature quickly and cycles on/off frequently, removes less humidity, wastes electricity, and risks failure. Right-sizing to the area is most efficient.
How do I convert to pyeong type?+
One Korean AC pyeong type is about 1,440 BTU (~363 kcal/h). E.g., 12,000 BTU ÷ 1,440 ≈ 8.3 pyeong type. Manufacturer ratings often build in a margin over actual area.
Why does sun exposure matter?+
South/west-facing rooms with strong sun gain radiant heat, raising the cooling load. High sun adds +10%, shaded rooms −10%. Large windows and high floors also increase the load.
Why size up for kitchens?+
Stoves and ovens generate a lot of heat. Kitchens and adjacent spaces need about +4,000 BTU for adequate cooling.
What if insulation is poor?+
Poor insulation/windows raise the cooling load, so add ~20% over this estimate to be safe. Conversely, new high-insulation builds have margin.
Cautions
- •Based on area × 600 BTU/m² plus adjustments. ±20% by insulation and windows.
- •Manufacturer pyeong ratings tend to build in margin.
- •Oversizing causes short cycling, poor dehumidification, wasted power.
- •Kitchens, high floors, large windows need more capacity.
- •For exact sizing, get an installer's on-site assessment.
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Last reviewed: 2026-05-30