What You’ll Learn
How can I check how much propane is left in my tank?
For large home tanks, read the float gauge on top—it shows the percentage of propane remaining (never above 80% for safety).
Never let it drop below 20% to avoid air getting into your system.
For smaller grill tanks, try the hot water test (feel for a cold spot) or weigh the tank against its stamped tare weight.
In this blog:
This blog was updated March 2026.
As winter gets closer, it’s time to find ways to stay warm.
That means putting on fuzzy socks, drinking hot chocolate, and turning on the heater.
Unless your heater can’t turn on, and if you run out of propane, there’s a high chance it won’t.
So how do you make sure your propane tank never empties out? It’s not as complicated as it might sound.
How to Check Above-Ground or Underground Propane Tank
When it comes to above-ground or underground propane tanks, the best way to figure out if your supply is getting low is by taking a look at the gauge.
Many tanks come with a gauge already installed, but you can also buy one and install it yourself if you need to.
The trick becomes knowing how to read your gauge and knowing when it’s time to refill. You don’t want to wait until your tank is completely empty to order more propane.
So how do you figure out the right time?
We’ll walk you through it.
Keep reading to learn how to find your tank, how to read your gauge, and how to find the right time to refill.
Finding Your Tank
If you have an above-ground propane tank, you can most likely skip this step. Don’t remember where it is? Just take a look around your property. You’ll be able to see it.
Finding an underground tank can be a bit trickier.
You have to look for a small plastic dome. This covers the gauge, valves, and other necessary parts.
It will be at least 10 feet away from your home or any other structure.
Once you locate your tank, you can take a look at the gauge.
Reading the Gauge
Because above-ground or underground propane tanks are a lot larger than grill tanks, they are often equipped with a float gauge system. This type of gauge is easy to read.
This system uses a floating component inside the tank. As it floats at the surface of your propane, it can estimate how much propane is left in your tank at all times.
The approximate level is displayed on the dial. When you check this dial, you should see a number between 10 and 80. This number is a percentage that tells you the rough amount of propane in your tank.
For example, if the dial says 65, you have about 65 percent of a tank.
But you can figure out exactly how much propane you have if you do some basic math.
First, convert the percentage into a decimal. Then multiply that decimal by the tank’s total capacity.
So let’s say your tank has a maximum capacity of 400 gallons. If your dial reads at 65 percent, you have 260 gallons left.
If you know how many gallons of propane you use every week, you can calculate your next refill time in advance. If not, make sure you check your tank often.
When Should You Refill Your Tank?
Remember, don’t wait until your propane tank is completely empty to refill it. If you do, you might end up with a few problems on your hands.
Air can work its way into your heating system when you get low on propane. Because the system runs on propane fuel, the air can cause pricey damage.
A professional propane company must restart your tank if it ever runs out of fuel.
To avoid these inconveniences, you’ll want to refill your tank when there’s still some amount of propane inside. Some homeowners like to be on the safe side and refill their tank when it reaches 30 percent. But many people wait until it gets to about 20 percent.
Try not to let your propane tank get below 20 percent without refilling. Your float gauge isn’t 100 percent accurate, so always stay cautious.
How Come My Tank is Never Full?
You might notice your gauge never gets above 80-85 percent. Don’t panic. This is normal.
Propane tanks must have enough room for the fuel to evaporate and turn into gas. The gas sits at the top of the tank, so you can’t fill the tank to its maximum capacity.
An above-ground tank can be filled to 80 percent, and an underground tank can be filled to 85 percent.
How to Check Your Grill’s Propane Tank
Checking the level of your grill’s propane tank is a little different than checking your above-ground or underground tank.
Why?
It’s smaller, so there are a lot of different ways you can find out how much propane is left.
Here are a few of the easiest methods that can let you know where you’re at.
Reading the Gauge
Sometimes it’s still a simple matter of reading the gauge. If the tank doesn’t have a gauge, you can buy one yourself and install it.
But for smaller tanks, you don’t have to rely on a gauge. There are several other ways you can find out how much propane remains.
The Hot Water Test
Take a bucket of hot water and dump it over your propane tank. Run your hand along the side of the propane tank.
The propane will absorb the heat. So if you feel a cold spot, that’s your propane.
You can use this method to roughly figure out the level of propane in your tank.
Weighing the Tank
Your propane tank will have a few numbers on the handle. One of these is the weight of your tank.
If you know how much your tank weighs and how much propane (in weight) it can hold, you can figure out the propane level with a scale. Most tanks weigh 17 pounds, and they can usually hold about 20 pounds of propane.
Pick up your tank and place it on your scale. Subtract 17 pounds from the total weight, and the remaining number represents how much propane you have inside your tank.
How to Tell if Your Propane Tank Is Empty
Running out of propane is a hassle. You need the fuel to power your home, and if that fuel is gone, you won’t be able to use normal household functions.
On top of that, without propane, air can get into your system and cause damage.
You can avoid these problems by never letting your propane run out.
For a large tank, the best way to do this is by reading the gauge. For smaller tanks, you can perform the water test or the weight test. Remember, never let your tank get below 20 percent.
Do you need to refill your propane tank? We can help! Make sure you take a look at some of our services.
Keep Your Home Fueled and Worry-Free
Need propane delivery or a new tank installation? We’ll handle everything—from same-day excavation to connection—so your home stays fueled without the hassle.
Become a Kauffman Gas customer today and let us install a high-quality tank wherever it works best for your property, above ground or underground.
FAQs
How do I know if my propane tank is empty?
You can check if your propane tank is empty by weighing it. Look for the tare weight (TW) stamped on the collar, weigh the tank, and subtract the TW to find the weight of remaining propane.
You can also perform the water test by running warm water down the side of the tank and feeling for a cool spot, which indicates the propane level. For larger tanks, simply read the gauge.
How do I check the propane level in my home tank?
Checking the level in a home tank can be done by reading the built-in gauge, which shows the fuel level as a percentage.
Some tanks use a pressure gauge, though this is less accurate because pressure fluctuates with temperature.
Newer tanks may have ultrasonic monitors that send readings directly to your smartphone.
What happens when a home propane tank runs out?
Running out of propane can cause several problems. Your heating and cooking appliances will stop functioning.
Air can enter the system, requiring a professional to bleed the lines before restarting.
You may also need a safety inspection before the system can be turned back on. In cold weather, a lack of propane can lead to frozen pipes and damage to appliances.
How do I know if I need a new propane tank?
Signs you might need a new propane tank include visible rust or significant physical damage, which can be safety hazards.
If you need more frequent refills than usual, it could indicate a leak or that the tank is no longer holding pressure.
Propane tanks typically last 10-30 years, so if yours is nearing that age range, consider replacement. Changes in safety regulations may also render older tanks non-compliant.