HVAC Tonnage Calculator
Sizing an air conditioner correctly matters — too small and it won't cool your home, too large and it wastes energy and wears out faster. Enter your home's square footage and climate zone to get a quick tonnage estimate.
About this calculator
Estimate the air conditioning tonnage your home needs based on square footage and climate zone to size a new HVAC system correctly.
Frequently Asked Questions
How accurate is this estimate?
This gives a rule-of-thumb estimate based on square footage and climate. A licensed HVAC contractor performing a Manual J load calculation will give you the most precise sizing, factoring in insulation, windows, and orientation.
What happens if my AC is oversized?
An oversized unit cools quickly but cycles on and off frequently, leaving humidity uncontrolled and increasing wear on components.
Does ceiling height matter?
Yes, taller ceilings mean more air volume to cool, so this calculator adjusts the estimate upward for ceilings above 8 feet.