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Furnace BTU Sizing Tonnage Calculator – Free & Easy to Quickly Find the Right Size
Welcome! START HERE:
Use the Gas Furnace sizing calculator below to calculate your required central heating system Btu size.
Follow these easy steps:
Upon calculating your gas furnace size (Btu), you will be shown a selection of gas furnaces that fit your recommended size.
Note: This calculator is not intended for use in sizing mobile home systems.
The sizing chart below is useful to help you determine your approximate central air conditioner size requirements.
If you still need help, don't worry! Chat with or call one of our factory trained advisors to help get you the answers you need. 1-866-862-8922
As an alternative to the sizing chart below we offer MANUAL J - a professional load calculation based on your floor plan, location, and all variables. Please follow the link below for pricing. The turnaround for this service is 1-2 days.
Heating Square Footage Range by Climate Zone
| ZONE 1 | ZONE 2 | ZONE 3 | ZONE 4 | ZONE 5 |
| 30 - 35 BTU's per square foot | 35 - 40 BTU's per square foot | 40 - 45 BTU's per square foot | 45 - 50 BTU's per square foot | 50 - 60 BTU's per square foot |