Is your furnace the right size?

Heating contractors routinely oversize residential equipment — sometimes more than double what a home actually needs. Oversized systems cost more upfront, short-cycle, and run less efficiently.

This calculator uses your natural gas bills and Environment Canada weather data to estimate the heating capacity your home genuinely requires. How it works →

Postal Code (first 3 characters are enough)

Consumption Unit ⓘ

Furnace Efficiency (AFUE %) ⓘ

Gas Consumption Data

Enter your gas bill data — each row needs a billing period start date, end date, and consumption amount. Use at least 12 months for a reliable result; 24 months is ideal. If you have significant gas usage in the summer (e.g. pool heater), you may get a better result if you omit those months.

Start Date

End Date

Consumption