Furnace Size Calculator
How to determine the correct furnace size for your home.
Furnace size is measured using the amount of heat it produces expressed in in BTU, which is short for British Thermal Unit.
The size of the furnace depends on the size and type of your home: bungalow, single, semi-detached or townhome. It also depends on whether it was built before or after the year 1980 as the regulations and standards have changed since then.
You can use How to Choose a Furnace