I have an older tank that I've never figured out how to 'read'. My calendar reminder told me that it was time to order, so I called the local AmeriGas office and requested a delivery. I was suspicious that the tank was getting pretty low, but knew it wasn't out.
My delivery was estimated to be the following week. Instead, I received my propane delivery the very next day and judging by the amount - I was closer to out than I had estimated.
Thank you, AmeriGas - for taking care of me!