Look at the top of your propane tank. You’ll see a round dial with readings going from 0 to 95. It is the gauge of your propane tank, designed specifically to give you readings. The numbers indicate the percentage of propane left in the tank. If you have trouble getting the reading, employ the hot water touch method or the weight method because it can be inaccurate at times. These are rough methods but are good for finding out immediate answers.