What Size Air Conditioner Do I Need? A Simple Guide for Homeowners
Getting the right air conditioner size is key to maintaining comfort and efficiency in your home. This guide walks you through measuring your space, calculating BTUs, and using our Cooling BTU Calculator for precise results.
1. Measure Your Space
Use a tape measure to record the length and width of the room in feet (or meters). Multiply these to find the square footage (or square meters) of the area you need to cool.
2. Calculate BTU Requirements
The general rule of thumb is 25 BTU per square foot. So, for a 12 ft × 12 ft room (144 sq ft), you'd need about 3,600 BTU.
3. Use Our Calculator
For even more accuracy, enter your measurements into our free BTU & Tonnage Calculator. It automatically converts units and sums total cooling requirements across multiple rooms.
4. Why Right Sizing Matters
An undersized AC will struggle to cool, driving up energy bills, while an oversized unit cycles on/off too frequently, causing wear and tear. Getting the size right optimizes comfort and efficiency.
Recommended AC Unit: For mid-sized rooms, we recommend the COSTWAY 12000 BTU Mini Split (Ad). It's energy-efficient, quiet, and easy to install.