How Long Does a Propane Tank Last on a 50,000 BTU Fire Pit?

A full 20-pound propane tank will run a 50,000 BTU fire pit for about 8½ hours if the burner stays at its maximum setting. That estimate comes from roughly 430,000 BTUs of energy in a 20-pound tank divided by a 50,000-BTU-per-hour burn rate; for a closer look at the calculation, see our guide to propane tank run time.

Turning down an adjustable flame uses less propane per hour, so the same tank can last longer than the full-output estimate. Tank fill level, burner setting, and outdoor conditions also affect how long you can enjoy the fire, so we recommend treating 8½ hours as a planning figure rather than an exact cutoff.

For a long gathering, start with a full tank and consider keeping a properly stored spare available rather than assuming a partly used tank will last all night. Our 9-Piece Outdoor Patio Set with 47″ Fire Pit Table & 50,000 BTU Propane Fire Pit has the 50,000 BTU rating used in this estimate, but your actual run time still depends on how high you set the flame.

Use the fire pit outdoors in a well-ventilated area, keep the propane tank upright, and follow the fire pit and tank instructions for placement and connections. If you change tanks, turn off the gas first and check the reconnected fittings for leaks with a soapy-water solution before lighting the burner; never test for leaks with a flame.