Gas Bill Calculator — From Therms Usage
Monthly Total
--
Total Therms
--
Usage Cost
--
Annual Estimate
--
How to Calculate Your Gas Bill
Natural gas is measured in therms (100,000 BTU). Your bill equals therms used times the rate per therm, plus a fixed monthly service charge. The average US household uses 50-100 therms per month, varying dramatically by season.
Space heating is the largest gas consumer (60-70% in winter months), followed by water heating (20-25%) and cooking/drying (5-10%). Summer gas bills are much lower since heating is not needed.
Gas rates average $0.80-$1.50 per therm depending on location and market conditions. Lowering your thermostat by 1 degree F saves about 3% on heating costs. A programmable thermostat can save 10-15% annually.
Frequently Asked Questions
What is a therm?
A therm is a unit of heat energy equal to 100,000 BTU. One therm is roughly the energy in 100 cubic feet of natural gas. It is the standard billing unit for natural gas in the US.
Why is my winter gas bill so high?
Heating accounts for 60-70% of gas usage. In cold months, a furnace may run 8-16 hours per day, consuming 3-8 therms daily. Insulation, window sealing, and thermostat management can reduce winter bills by 20-30%.
Gas vs electric heat - which is cheaper?
Natural gas heating is typically 30-50% cheaper than electric resistance heating. However, electric heat pumps are 2-3x more efficient than gas furnaces and may be cheaper in moderate climates.