How to Choose the Right BTU for Your Room

Learn how to calculate the perfect air conditioner capacity for any room size. Avoid overspending on oversized units or suffering with undersized ones.

Choosing the right BTU (British Thermal Unit) capacity for your air conditioner is crucial for comfort and energy efficiency. An undersized unit will struggle to cool your space, while an oversized one will cycle on and off frequently, wasting energy and failing to dehumidify properly.

Understanding BTU

BTU measures the amount of heat an air conditioner can remove from a room per hour. The higher the BTU, the larger the cooling capacity.

Basic Calculation

As a general rule, you need approximately 20 BTU per square foot of living space. However, several factors can affect this:

  • Ceiling height: Rooms with ceilings higher than 8 feet need more BTU
  • Sun exposure: Add 10% for sunny rooms
  • Kitchen: Add 4,000 BTU for kitchens
  • Occupancy: Add 600 BTU per person beyond 2

Quick Reference Chart

Here's a quick guide based on room size:

  • 150-250 sq ft: 6,000 BTU
  • 250-350 sq ft: 8,000 BTU
  • 350-450 sq ft: 10,000 BTU
  • 450-550 sq ft: 12,000 BTU
  • 550-700 sq ft: 14,000 BTU

Use Our Calculator

For a more accurate calculation, use our BTU Calculator which considers all these factors automatically.