Question: how do i know how much propane is left?
Answer: Most propane tanks weigh around 18 1/2 pounds when they are empty. Place your tank on a household scale and subtract 18 1/2 from that number. From there, you can determine how much you have left. An average size (500 sq-in) grill will use about 1 1/2 pounds of propane an hour cooking medium to high.