Window Air Conditioner Size Calculator — Find the Right BTU for Your Room

Window Air Conditioner Size Calculator

Find the perfect window air conditioner size (BTU) for your room based on dimensions, insulation, climate, and other factors. Avoid buying an undersized or oversized unit.

Step 1: Room Details

8 ft

Understanding BTU Requirements

BTU (British Thermal Unit) measures cooling capacity. Choosing the right size ensures efficient cooling, lower energy bills, and longer equipment life. An undersized unit won’t cool properly, while an oversized one cycles too frequently.

Step 2: Additional Factors

2 people
2 windows

About AC Sizing

Proper AC sizing is crucial for comfort and efficiency. As a general rule, you need about 20 BTU per square foot of living space. However, this can vary based on ceiling height, insulation, sunlight exposure, and other factors.

Air Conditioner Size Results

Summary
AC Size Comparison
Room Analysis

Recommended AC Size

6,500 BTU
Room Area: 180 sq ft
Room Area
180 sq ft
Recommended BTU
6,500 BTU
Equivalent Tons
0.54 tons
AC Type
Window Unit

Air Conditioner Size Comparison

BTU Range Room Size (sq ft) AC Type Typical Usage Power Consumption

Room Cooling Analysis

BTU Calculation Formula

BTU = (Room Area × 20) × Ceiling Height Factor × Insulation Factor × Climate Factor × Room Type Factor + (Occupants × 400) + (Windows × 200)

Base calculation assumes 20 BTU per square foot. Adjustments are made for ceiling height, insulation quality, climate, room type, number of occupants, and windows. Kitchen adjacency adds 10% to the total.

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