UnitsUp to date · Jan 15, 2026
Therm
A unit of heat energy equal to 100,000 BTU. Natural gas bills for residential customers are typically measured in therms. One therm is roughly equivalent to 100 cubic feet (1 Ccf) of natural gas.
Why It Matters
If you have a gas furnace, water heater, or stove, your gas bill is measured in therms. Understanding this unit helps you compare the cost of gas vs. electric heating.