Your propane gas gauge is located under the dome at the top of the tank. Reading your propane gas gauge is not complicated. You’ll see bold black numbers encircling the gauge and a single pointer needle. The pointer will indicate a number that represents a percentage.
Due to the physical properties of propane, your tank is considered full at 80% (allowing for the expansion of propane vapor). A propane tank is in IMMEDIATE NEED of refilling at 20%. For your safety and protection, it is best to fill your tank BEFORE the gauge goes below 20%.
This chart shows how many gallons of propane you have in your tank at a given percentage.