A propane tank can be a useful thing to have around for any number of purposes. Whether you use your tank to heat your water heater or to keep the grill running during barbecue season, every homeowner should keep an eye on the propane levels. Propane tanks need refilling at around 20 percent, but there’s no gauge on the side of your tank that tells you when it’s getting low. Use one of these four helpful methods to determine when your tank needs to be refilled.

The Weight Test

Your propane tank is obviously going to get lighter the more you expend gas in it, but just picking it up to feel the weight can be an inaccurate method for determining when it needs to be replaced. If you want to consistently use weight to determine when it’s time for a change, you’ll want to invest in a scale. A typical propane tank weighs 17 pounds when empty and can retain 20 pounds of fuel. That means that your tank should weigh roughly 21 pounds when it’s time to get topped off. Just keep in mind that weight may vary from tank to tank, so you may want to consider weighing your tank after a refill to get a better estimate.

The Water Test

If you don’t want to invest in a scale or can’t find one around the house, you can get an estimate of your propane levels with a simple glass of water. For your safety, you’ll want to turn off the propane tank and disconnect it from its source. Heat up the water, then pour it down the side of the tank from the top down. The surface of the tank will become hot where it’s empty and stay cold where there’s still propane. While it’s not the most accurate method of measurement, it can be a great way to check the levels when you’re pulling out an old tank for grilling season.

Cook Time Measurements

While paying attention to your cook times isn’t a great way to determine how much propane you have in your tank in the moment, it can be used to help you determine how much life you can get out of it. This requires a little math, but it can provide you with a sensible ballpark estimate when you’re looking to cook. A gallon of propane burns about 92,000 BTUs, so all you have to do is divide that number by the BTU per hour of your grill and multiple by the number of gallons in your tank. If you’re planning on spending a long weekend grilling in the backyard, this method can save you an unnecessary hassle.


There are a number of gauges you can invest in that will give you an accurate reading of your propane level. Inline pressure gauges, digital scales, and analog propane scales all function differently but ultimately produce the same results. If you’re looking for an accurate reading that requires little work on your part, these are the best options available to you.

Running out of propane can be a hassle when you’re using it to power your grill or a potential hazard if it’s the main source of heating in your home. One way or another, a little effort can go a long way, and checking your propane levels on a semi-regular level can spare you some grief.

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