HVAC Sizing Calculator
Estimate system size for your home. A 2,000 sq ft house in a mixed climate needs about 40,000 BTU of cooling, roughly 3.33 tons.
Rule of thumb sizing
This calculator uses simple BTU per square foot factors: roughly 18 to 25 BTU for cooling and 25 to 45 for heating depending on climate, adjusted for insulation and ceiling height. A 2,000 sq ft mixed-climate home gives about 40,000 BTU of cooling (3.33 tons) and 70,000 BTU of heating.
Manual J is the real answer
Professional contractors use a Manual J load calculation that accounts for windows, orientation, air leakage and duct losses. Use this tool for budgeting and to sanity check quotes. If a contractor proposes a unit much bigger than the estimate here, ask for the load calculation.
- Oversized AC short-cycles and fails to dehumidify.
- Better insulation and air sealing can shrink the system you need.
- Furnace size depends on climate and design temperature.
For a single room use the BTU calculator.
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Frequently asked questions
What size AC do I need for 2,000 square feet?
Typically 3 to 4 tons depending on climate and insulation.
How many square feet does a ton cover?
Roughly 400 to 600 square feet per ton depending on climate and home quality.
Is this a replacement for Manual J?
No. It is a quick estimate. A Manual J load calculation is the accurate method.
Should I round up the size?
Round to the nearest standard size. Avoid big upsizing.
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