A therm is a unit of heat or energy. A therm, whether a natural gas therm or a propane therm is the same thing. A therm is equal to 100,000 British Thermal Units (BTU). A BTU is equal to the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit. One gallon of propane contains about the same amount of energy as about 91 cubic feet of natural gas.
Convert Propane Gallons to Therms
Multiply the number of gallons of propane by 91,647 to get the number of British Thermal Units because one gallon of propane equals 91,647 BTUs.
Multiply the number of gallons of propane by .91647 to get the number of therms. This is because one therm equals 100,000 BTUs.
Multiply the number of gallons of propane by 91.647 to get the approximate equivalent cubic feet of natural gas that has the same energy. This is because one cubic foot of natural gas is equal to about 1000 BTUs.