How Long Does a 20 lb Propane Tank Last?
A standard 20 lb propane tank typically lasts about 18 to 20 hours when used with a typical backyard gas grill. The exact runtime depends on the grill’s heat settings, burner output, and how long you cook.
Most propane grills use between 20,000 and 30,000 BTUs per hour. At that rate, a full 20 lb propane cylinder usually provides several cooking sessions before needing to be refilled or exchanged.
Quick answer: A full 20 lb propane tank usually lasts 18–20 hours on a standard gas grill, but the actual time can vary depending on the heat setting and grill size.
Average Propane Tank Runtime by Appliance
Propane usage varies depending on what appliance is using the tank. Grills, patio heaters, and smokers all consume propane at different rates.
| Appliance | Typical Runtime (20 lb Tank) |
|---|---|
| Gas grill | 18–20 hours |
| Patio heater | 8–12 hours |
| Propane smoker | 15–20 hours |
| Camping stove | 15–25 hours |
What Affects How Long a Propane Tank Lasts?
Several factors influence how quickly propane is used.
- Grill heat settings – Higher temperatures burn propane faster
- Number of burners – Using multiple burners increases fuel use
- Outdoor temperature – Cold weather can affect propane pressure
- Cooking time – Longer grilling sessions use more fuel
If you frequently cook at high heat or run multiple burners, your propane tank may run out sooner than expected.
How to Tell When Your Propane Tank Is Running Low
It is helpful to check your propane level before cooking so you do not unexpectedly run out of fuel.
You can estimate propane levels using several simple methods, including the hot water test or weighing the tank. For a full explanation, see our guide on how to tell if a propane tank is empty.
What to Do When Your Propane Tank Runs Out
If your propane tank runs out, you have two main options: exchange the tank or refill it.
- Propane exchange: Swap your empty tank for a prefilled one at many retailers
- Propane refill: Refill the same tank at a propane refill station
Exchange services are widely available at grocery stores, hardware stores, and big retailers. You can find common locations in our guide to propane tank exchange near you.
If you want to compare pricing, see our guide on propane tank exchange cost.
Frequently Asked Questions
How many grilling sessions does a propane tank last?
A 20 lb propane tank usually lasts about 7 to 10 average grilling sessions, depending on how long each session lasts and the heat settings used.
How much propane is in a standard grill tank?
A standard grill cylinder holds up to 20 pounds of propane. However, many propane exchange programs fill tanks with about 15 pounds for safety and transportation reasons.
Can propane tanks run out suddenly?
Yes. Propane tanks often seem to run out suddenly because propane pressure drops quickly near the end of the tank. Checking the tank level before cooking can help avoid unexpected interruptions.
Conclusion
A typical 20 lb propane tank lasts about 18 to 20 hours when used with a standard gas grill. Actual runtime depends on heat settings, appliance type, and cooking duration. Checking your propane level regularly can help ensure you always have enough fuel for your next cookout.