Building tool

AC Tonnage Calculator

Estimate air-conditioner tonnage and BTU capacity from conditioned area and climate load.

Runs in your browser
AC Tonnage Calculatorupdates live
Result
Estimated load
47,520 BTU/hr
Calculated tonnage
3.96
Nearest half ton
4
Suggested airflow
1,584 CFM

Oversizing can reduce comfort and humidity control. Confirm equipment with a licensed professional and a room-by-room load calculation.

How to use this AC tonnage calculator

  1. Enter the conditioned area, ceiling or climate details, and the heat-load adjustments shown in the form.
  2. Review the calculated totals, units, and assumptions. Check the inputs and units before relying on the result.
  3. Change one input at a time to compare another case, then copy or save the result you plan to use.

About this AC tonnage calculator

The AC Tonnage Calculator lets you estimate air-conditioner tonnage and BTU capacity from conditioned area and climate load. The controls cover only the inputs needed for the result.

You can also use it to compare results after changing one input.

Example

Use the AC Tonnage Calculator for a 1,500 square foot conditioned space, then adjust for climate, ceiling height, windows, and occupancy.

Common uses

  • estimate air-conditioner tonnage and BTU capacity from conditioned area and climate load
  • compare results after changing one input
  • save an estimate for planning or comparison