How Many BTUs Are in Propane?

This Energy Measurement Helps You Compare Fuels

Did you know that propane generates a lot more Btu than an equivalent amount of electricity? This means you need much less propane to produce the same amount of heat energy. That’s a big reason why propane is better for the environment. Because the less energy you use, the greener you are.

To appreciate propane’s big advantage over electricity in energy efficiency, let’s take a closer look at BTU content.

According to the U.S. Energy Information Administration, a British thermal unit (Btu) is a measure of the heat content of fuels or energy sources. It’s measured by the quantity of heat that’s required to raise the temperature of one pound of water by one degree Fahrenheit–at the temperature in which water has its greatest density (approximately 39 degrees Fahrenheit).

What Propane BTU-Per-Gallon Tells Us

BTUs can be used to compare energy sources on an equal basis. To compare propane to electricity, we need to know that:

• one gallon of propane = 91,452 Btus
• one kilowatt hour (kWh) of electricity = 3,412 Btu

To make these two energy sources “equal,” divide 91,452 Btus by 3,412 Btu. Your answer will be:

• One gallon of propane = 27 kWh of electricity. In other words, one gallon of propane contains the same amount of usable energy as 27 kilowatt hours of electricity.

Propane101.com makes this comparison to illustrate the efficiency of propane compared to electricity. A 100-watt light bulb left on for a full day–24 hours–will consume 2.4 kWh. If propane could be used to power the same light bulb. it would only use 9/100th of a gallon of propane.

How Much Propane Will I Use?

Thanks to BTU telling us how much heat energy is in a gallon of propane, we can make estimates about how much fuel the average homeowner will use. The estimates below are expressed as BTU per hour. This is a way to represent a measurement of deliverable power applicable to each propane gas appliance. (Think of it like the horsepower rating of a car). As an example, a typical furnace is about 100,000 BTU per hour. You can go here to read more about BTU per hour.

• Furnace – 100,000 to 200,000 BTU/hour: about 1 to 2 gallons/hour
• Fireplace with ceramic logs – 26,000 BTU/hour: 1 gallon / 3 hours
• Gas cooktop/range – 65,000 BTU/hour: 5 to 10 gallons / month)
• Tankless water heater – 40,000 BTU/hour (about 1.5 gallons /day)
• Gas clothes dryer – 35,000 BTU/hour: less than 1 gallon/ day)

Read more about the benefits of propane.