The Bertello Propane Burner uses 16,000 BTUs. You can also purchase a NG Burner if you have a home natural gas sytstem. A 20 lb propane tank typically holds 430,000 BTUs when full. If you use the oven on the highest setting with gas only, using 16,000 BTU’s per hour (430,000 divided by 16,000 = 26.875), the tank should last over 26 hours of cooking.