How to estimate heating cost
Combine house size, winter severity and fuel price.
Enter the heated area
Use the floor area you actually heat, not the full footprint of the building.
Pick a climate band
Choose the band that matches a typical winter in your location.
Adjust fuel and efficiency
Use your tariff and the furnace or boiler efficiency from its label.
What does this tool do?
Heating demand rises with floor area and the severity of the winter, while fuel price and equipment efficiency decide what that heat costs. This calculator uses a simple climate intensity figure and converts delivered heat into fuel units.
The Formula
Seasonal heat = area × climate intensity; fuel units = heat ÷ efficiency ÷ energy per unit; cost = units × priceFrequently Asked Questions
What is a heating degree day?
It measures how far the average outdoor temperature falls below a reference temperature, typically 65°F. More degree days mean more heating energy for the same house.
Is a heat pump cheaper than gas?
It depends on local prices and the heat pump efficiency. Compare the cost per unit of delivered heat, not the price per unit of fuel.