Short-filling tanks by about 25%! Standard barbeque tanks hold just under 20 pounds of propane(4.6 gallons). Pick-up propane fills to 15 lbs., about 25% less than if you got your tank filled in front of you. I’ve used them before, purchasing from De Naults Hardware, and the tanks felt LIGHT. Weighing them on a scale confirmed. They charge similar prices to other tank exchanges, but sell you 25% less product. Calculations: Standard 20-pound tank holds 5.7 gallons. 82% fill for safety = 4.6 gallons. 4.6 gallons X 4.2 pounds per gallon of propane = 19. pounds of propane, if filled. Per label on tank, Pick-up fills to 15 lbs.