Whether you are heating an RV, grilling in the backyard, or running a propane furnace for your home, understanding your fuel consumption is vital for budgeting and ensuring you don't run out of fuel unexpectedly. This calculator converts your appliance's energy rating (in BTUs) into tangible metrics like gallons and pounds of propane consumed.
How the Calculation Works
Propane consumption is calculated based on the energy density of the fuel. The standard industry values used in this calculator are:
1 Gallon of Propane = Approximately 91,500 BTUs.
1 Pound of Propane = Approximately 21,548 BTUs.
Density: There are approximately 4.24 pounds of propane in 1 gallon.
To determine how much fuel you use, we divide your appliance's BTU rating by 91,500 to find the gallons burned per hour, then multiply by the duration of usage.
Common Appliance BTU Ratings
If you aren't sure of your appliance's exact rating, you can use these average ranges as a reference:
Appliance Type
Typical BTU Range (Per Hour)
Avg. Gallons Used Per Hour
RV Furnace
20,000 – 35,000 BTU
0.22 – 0.38 gal
Gas Grill (Medium)
30,000 – 40,000 BTU
0.33 – 0.44 gal
Propane Fireplace
20,000 – 40,000 BTU
0.22 – 0.44 gal
Home Furnace
60,000 – 100,000 BTU
0.65 – 1.09 gal
Tankless Water Heater
150,000 – 199,000 BTU
1.64 – 2.17 gal
Example Calculation
Let's say you are running an RV Furnace rated at 30,000 BTUs and you plan to run it for 8 hours overnight. The price of propane is currently $2.80 per gallon.
Gallons per hour: 30,000 / 91,500 = 0.328 gallons per hour.
Total Usage: 0.328 gallons/hr × 8 hours = 2.62 gallons.
Total Cost: 2.62 gallons × $2.80 = $7.34.
In this scenario, a standard 20lb BBQ tank (which holds about 4.7 gallons) would last roughly 14 hours if running continuously.
Frequently Asked Questions
How many gallons are in a standard 20lb tank?
A standard "20lb" propane tank (commonly used for grills) typically holds about 4.7 gallons of propane when full, assuming the tank is filled to the safe 80% capacity limit.
Does outside temperature affect propane usage?
Indirectly, yes. While the BTU rating of the appliance doesn't change, colder temperatures usually mean furnaces and heaters must run longer or more frequently to maintain a set temperature, increasing overall consumption.
Why is my usage higher than calculated?
Appliance efficiency plays a role. Older appliances may not operate at 100% efficiency, meaning they might consume the same amount of fuel but produce less effective heat, causing you to run them longer.