Heating and cooling bill

What does a year of heating and cooling cost?

This is not an install price and it is not your utility bill. It is a planning year so a furnace quote and a heat-pump quote have something to sit next to besides a brochure. You get three numbers for the home size you set, in the city you set. Gas heat. Heat-pump heat. Cooling. They are not added into one cost of living, because adding them hides which one is the problem.

The arithmetic is on purpose, and it is simple

Gas therms equal heating degree days times square feet times 0.00012. A 1,800 square foot house in a 4,000 degree-day climate is about 864 therms. Those therms are priced at whatever you type in the bar, which starts at $1.50. Wellholt has a local electric rate for each city and does not have a local gas tariff, so it will not invent one and call it yours. If your utility charges a different price per therm, change the bar and the gas line moves. Heat-pump kilowatt-hours take those therms, convert at 29.3 kilowatt-hours per therm, and divide by 2.6. The 2.6 is a planning efficiency, not the sticker in a showroom. Those kilowatt-hours use your city’s electric rate. Cooling kilowatt-hours equal cooling degree days times square feet times 0.0012, at the same electric rate.

The low column on the city page is 85 percent of that planning year. The high column is 120 percent for heat and 125 percent for cooling. That is a stand-in for an easier or harder weather year, not a repair and not a second house. A tighter house, a worse house, a different thermostat, or a wood stove will not match the middle.

What the city actually changes

Degree days change the therms and the cooling kilowatt-hours. The electric rate changes the heat pump and the cooling dollars. Gas dollars change only when you change the price per therm in the bar. They do not change because the city changed. A hot city with a high rate is a cooling problem. A cold city with a low rate can still be a heating problem if the degree days are large. The city page writes both degree-day numbers next to the three dollars. Use that page when you want the example house. Use this calculator when the square footage is yours.

How to sit this next to a quote

The furnace calculator has the install price. This one has the year after. If gas heat is cheaper per year than the heat pump, that is not the end of the decision: the heat pump also covers cooling, which is the third number, and the install gap is on the other page. Do not divide an install difference by a yearly difference and call it a payback unless both numbers are for your house, your rate, and a gas price you actually pay. If your gas is not the $1.50 the bar starts at, type the price from your bill. Do not change the degree days to force the answer. A salesperson who quotes yearly savings with no degree days and no rate is asking you to trust a slogan.

What this will not do

It will not read your meter. It will not apply a time-of-use rate, a winter gas slope, or a budget plan that hides July. It will not tell a renter to buy a furnace. A renter can still use it to see why a cheap rent in a hot city is not a cheap year. Owners should set square footage before they treat the city example as their bill. Reviewed as a method on 2026-09-30.

If you want the install price, leave this page. The furnace, the roof, the attic, and the water heater each have their own range. Mixing a yearly bill into an install table is how a fair furnace starts to look expensive, or cheap, for a reason that is not on the quote.