Propane Usage Calculator
Enter your appliance's BTU rating, how long it runs and your tank size. You get how long the tank lasts and what it costs per month.
How the propane usage calculator works
One gallon of propane holds about 91,500 BTU. An appliance's gallons per hour is its BTU rating divided by 91,500, at full flame. Divide the propane in the tank by that rate to get hours of use.
Common tank amounts: a 20 lb grill tank holds 4.7 gallons, a 100 lb cylinder about 23.6 gallons, and a 500 gallon tank about 400 gallons, because large tanks are only filled to 80%. Appliances that cycle on and off, like furnaces and water heaters, burn less than their rating over a full day, so enter the hours they actually run.
Questions
How long does a 20 lb propane tank last on a fire pit?
A 60,000 BTU fire pit at full flame burns about 0.66 gallons an hour, so a 20 lb tank (4.7 gallons) lasts about 7.2 hours.
How long does a 500 gallon propane tank last?
A 100,000 BTU furnace that runs 8 hours a day burns about 8.7 gallons a day, so 400 gallons lasts about 45.7 days.
How much propane does a 40,000 BTU heater use per hour?
About 0.44 gallons, or 1.85 lb, per hour at full output.