Heating Cost Calculator

Calculate your gas bill per year and per month, how much of it goes to heating, and what turning the thermostat down saves.

It is on your annual statement or in your utility's app.

Your price per therm, including taxes and delivery charges: about 1.50 on average for US homes.

Fixed charges for your gas supply per year, such as the monthly customer charge. The default is 0, because the average US price per therm already includes them.

The rest goes to hot water and cooking. Often about three quarters of the gas is for heating.

How many degrees you turn the thermostat down, on average over the day.

The US Department of Energy says turning the thermostat back 7 to 10 °F for 8 hours a day saves up to 10% a year. Lowered all day, that comes to roughly 3% per °F, or about 5.5% per °C.

Show gas in

The unit the calculator uses to show an amount of gas.

Please check

Heating cost per year

$855.00

Per month

$71.25

Of which heating

$598.50

Saving with the thermostat lower

$35.91

Gas saved per year

24 therms

Please note: The result is an estimate and has been rounded. Actual costs and values may differ, and no rights can be derived from this calculation.

Gas use varies from year to year with the weather; the saving per degree is a rule of thumb.

How this number is calculated

The blocks use your input. Change a value above and they update with it.

Step 1 · Gas cost without fixed charges

Natural gas use per year1,709.4231 m³ × Natural gas price$0.5002 per m³ =Gas cost without fixed charges$855.00

Step 2 · Heating cost per year

Gas cost without fixed charges$855.00 + Fixed gas charges per year$0.00 =Heating cost per year$855.00

Step 3 · Gas for heating

Natural gas use per year1,709.4231 m³ × Share for heating (%)70 ÷ Per100 =Gas for heating1,197 m³

Step 4 · Saving on heating

smallest ofThermostat lower (degrees)2 × Saving per degree (%)3 Per100 =Saving on heating6 %

Step 5 · Gas saved

Gas for heating1,197 m³ × Saving on heating6 % ÷ Per100 =Gas saved72 m³

Step 6 · Saving with the thermostat lower

Gas saved72 m³ × Natural gas price$0.5002 per m³ =Saving with the thermostat lower$35.91

How the calculation works

Calculate what you spend on natural gas per year and per month, how much of it goes to heating, and what it saves to turn the thermostat down.

Your heating cost is your gas use times the gas price, plus the fixed charges for the gas supply. Not all gas goes to heating: some is for hot water and cooking. When you turn the thermostat down, you save on the gas for heating. The calculator uses a fixed percentage per degree, a common rule of thumb.

Formula

Heating cost = gas use × gas price + fixed charges. Gas for heating = gas use × share for heating. Gas saved = gas for heating × degrees lower × saving per degree (at most 100%). Saving = gas saved × gas price.

Assumptions

  • The gas price is a fixed rate per unit, including taxes.
  • The saving per degree is a rule of thumb; in a well-insulated home it is often smaller, in a drafty home larger.
  • The gas use is for a year with ordinary weather. A cold winter costs more.
  • Internally the calculator uses Dutch gas at 9.77 kWh per m³. kWh and therms convert exactly; UK and US gas holds more energy per m³.

Example calculations

The button fills in the calculator above, so you can carry on from there.

  • Home using 1,200 m³ of gas

    Heating cost per year

    $1,980.00

    Natural gas use per year 1,200 m³ · Natural gas price $1.35 per m³ · Fixed gas charges per year $360.00 · Share for heating (%) 72 · Thermostat lower (degrees) 1 · Saving per degree (%) 10

  • Two degrees lower

    Heating cost per year

    $1,980.00

    Natural gas use per year 1,200 m³ · Natural gas price $1.35 per m³ · Fixed gas charges per year $360.00 · Share for heating (%) 72 · Thermostat lower (degrees) 2 · Saving per degree (%) 10

  • Small apartment

    Heating cost per year

    $810.00

    Natural gas use per year 600 m³ · Natural gas price $1.35 per m³ · Fixed gas charges per year $0.00 · Share for heating (%) 70 · Thermostat lower (degrees) 1 · Saving per degree (%) 10

Frequently asked questions

What does turning the thermostat down save?

With 12,000 kWh of gas a year, 72% of it for heating, and 5.5% saving per degree, turning down by 1 degree saves 475 kWh, or 38.02 a year at 0.08 per kWh.

Why is my heating cost different every year?

How much you heat depends a lot on the weather. A cold winter uses more gas than a mild one. Compare several years, or use an average.

Is the saving per degree Celsius or Fahrenheit?

Per degree on your own thermostat. The default of 3% is per degree Fahrenheit; per degree Celsius it is about 5.5%. Enter the degrees and the percentage in the same unit.

What are the fixed charges?

The customer charge or standing charge for your gas connection. You pay it however little gas you use; it only goes away if you stop using gas altogether.

What if I get a heat pump?

Then you use less gas and more electricity. The heat pump calculator shows what that changes per year and how long a heat pump takes to pay back.

Sources and checks

Sources

How we check it

This calculator has 10 fixed checks: 7 calculations with a result that is fixed in advance, and 3 cases of invalid input that must be rejected. They all run automatically every time we publish; if one fails, the calculator does not go live.

See the calculations
  • Natural gas use per year 1,200 m³ · Natural gas price $1.35 per m³ · Fixed gas charges per year $360.00 · Share for heating (%) 72 · Thermostat lower (degrees) 1 · Saving per degree (%) 10 → Heating cost per year $1,980.00
  • Natural gas use per year 1,200 m³ · Natural gas price $1.35 per m³ · Fixed gas charges per year $360.00 · Share for heating (%) 72 · Thermostat lower (degrees) 2 · Saving per degree (%) 10 → Heating cost per year $1,980.00
  • Natural gas use per year 600 m³ · Natural gas price $1.35 per m³ · Fixed gas charges per year $0.00 · Share for heating (%) 70 · Thermostat lower (degrees) 1 · Saving per degree (%) 10 → Heating cost per year $810.00
  • Natural gas use per year 1,500 m³ · Natural gas price $1.40 per m³ · Fixed gas charges per year $300.00 · Share for heating (%) 80 · Thermostat lower (degrees) 0 · Saving per degree (%) 6 → Heating cost per year $2,400.00
  • Natural gas use per year 1,000 m³ · Natural gas price $1.40 per m³ · Fixed gas charges per year $0.00 · Share for heating (%) 100 · Thermostat lower (degrees) 5 · Saving per degree (%) 30 → Heating cost per year $1,400.00
  • Natural gas use per year 12,000 kWh · Natural gas price $0.08 per kWh · Fixed gas charges per year $108.00 · Share for heating (%) 72 · Thermostat lower (degrees) 1 · Saving per degree (%) 5.5 → Heating cost per year $1,068.00
  • Natural gas use per year 410 therms · Natural gas price $2.05 per therm · Fixed gas charges per year $150.00 · Share for heating (%) 75 · Thermostat lower (degrees) 2 · Saving per degree (%) 6 → Heating cost per year $990.50
Changes
  • : Separate default values, units and sources for the UK and the US: gas in kWh or therms, typical use, prices, share for heating and the saving per degree.
  • : First version. Defaults follow the Ofgem price cap (gas 0.08, standing charge 108); the saving per degree is now 5.5% per °C, derived from the US Department of Energy. Sources added.

Last reviewed: · How we build and check our calculators

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