See How Much Propane Is Left In Your Grill's Tank With This Water Hack

Gas grills are a godsend for busy cooks. With just a flick of a switch, you can have perfect grilled steaks and juicy burgers ready within minutes, without the fuss and mess of charcoal or hardwood. The main challenge is to ensure you have enough propane in your grill's tank to get you through the meal. Fortunately, an easy hack lets you do this even if your model doesn't have a built-in fuel gauge –- all you need is warm water and your hand.

To get a rough idea of how much propane is left, just pour warm water over the tank, and then run your hand down its side. You'll notice that the top part of the tank will feel warm (from the water), but as you run your hand toward the bottom, at some point it will feel cool. This cool zone reflects your propane level: If most of tank feels cold, you still have plenty of fuel. But if most of it feels warm, it's time for a refill.

The warm water hack may seem counterintuitive –- who would think that a highly flammable gas would make a container feel cool to the touch? But there's a simple scientific explanation: Propane responds to heat differently than metal. In technical terms, propane has a much higher heating point than the steel used to make the tanks. This means the amount of energy needed to heat propane is higher than that needed to warm up the steel.

As a result, when you pour warm water on it, the metal surface heats faster than the propane inside. This is why you feel a drop in temperature as soon as you reach the level where the propane exists. It's not because the fuel itself is cold; it's because it doesn't heat up as easily. While this warm water hack can't tell you exactly how much fuel you have left, it's accurate enough to help you know how much you need to replace to fill it back up again for a stress-free cookout.

While the warm water hack is the easiest way to get a sense for how much propane you have left, other methods let you get more accurate readings. One option is to use a tank with a built-in fuel gauge, or to purchase an external gauge from a home repair store. These work by using the tank's internal pressure to measure the fuel level and give readings as a percentage of the tank's total capacity.

If you have a scale, you can also measure your propane level by weight. Just put your tank on the scale and subtract the weight of it, which is typically stamped on its side. This will let you know how many pounds of fuel you have left. (For reference, standard propane tanks hold 20 pounds of fuel.) Even more convenient is to seek out a vendor that uses smart monitors. These monitors track propane levels and automatically notify the vendor to send a refill when you're close to running out.