Central AC System GuideCentral AC tool
AC Tonnage Sizing Calculator
Estimate central AC tons and BTU/h from home square footage and a broad climate factor before getting a professional Manual J load calculation.
Screening estimate only.A professional Manual J load calculation is authoritative for final central AC sizing and equipment selection. Confirm any decision with a licensed HVAC pro.
Screening result
Fine Print and Sources
Screening estimate only. These tools use only the values you enter and simple planning math. A professional Manual J load calculation is authoritative for equipment sizing, room loads, and final purchase decisions. Confirm with a licensed HVAC pro before you buy.
The square-feet-per-ton factors are broad screening estimates. One ton equals 12,000 BTU/h. Oversizing hurts comfort because a too-large system short cycles, cools fast without removing humidity, and leaves the home clammy. A Manual J load calculation, not a square-foot rule, sets the right size.
- EnergySage central air conditioner sizing guide: explains square-feet-per-ton screening ranges, notes one ton equals 12,000 BTU/h, and warns that oversizing causes short cycling and poor humidity control.
- ENERGY STAR central air conditioning: describes right-sizing and efficiency selection for central AC equipment.