Most US barbecue grills run on a 20 lb propane tank measuring roughly 18 inches tall and 12 inches across, and the grill manual’s approved cylinder size always overrides any generic chart.
Buy the wrong cylinder and you find out at the worst moment — the tank doesn’t fit the cabinet cutout, the collar won’t clear the lid, or the fitting won’t seat. Getting the size right takes about two minutes of measuring. The dimensions below cover the cylinders you’ll actually see at a US hardware store, followed by how to match one to your grill.
What Are The Standard BBQ Propane Tank Sizes?
The 20 lb cylinder is the default for American barbecue grills, and everything smaller is a portability trade while everything larger is a runtime trade.
- 5 lb: about 12 in tall × 8 in diameter — small portable grills and tabletop models.
- 10 lb: about 17.4 in × 8.9 in — camping and tailgate grills.
- 11 lb squatty: about 12.75 in × 12 in — fits low-clearance grills where height is the problem.
- 20 lb: about 18 in × 12–12.5 in — the standard full-size grill tank.
- 30 lb: about 23.4–24 in × 12.2–12.5 in — longer cooks on the same footprint.
- 40 lb: about 29.4 in × 12.2 in — high-consumption setups.
- 100 lb: about 46.6–48 in × 14.7–15.1 in — fixed installations, not tanks you carry.
AmeriGas, Ferrellgas, and Superior Plus Propane all publish slightly different figures for the same nominal size, which tells you something important: there is no single universal standard. A 20 lb cylinder is listed at 18 × 12 in by one supplier and 17.8 × 12.3 in by another. That variation is normal, and it’s why you measure rather than assume.
| Cylinder Size | Typical Dimensions | Best For |
|---|---|---|
| 5 lb | 12 in × 8 in | Tabletop and camping grills |
| 10 lb | 17.4 in × 8.9 in | Tailgating, small portables |
| 11 lb squatty | 12.75 in × 12 in | Grills with limited vertical clearance |
| 20 lb | 18 in × 12–12.5 in | Standard full-size BBQ grill |
| 30 lb | 23.4–24 in × 12.2–12.5 in | Longer cooks, same footprint |
| 40 lb | 29.4 in × 12.2 in | High-consumption grilling |
| 100 lb | 46.6–48 in × 14.7–15.1 in | Fixed installations only |
How Do You Choose The Right Cylinder For Your Grill?
Start with the grill manual, because the manufacturer’s approved cylinder size is the only specification that actually governs the purchase.
Three checks settle it:
- Confirm the manual’s specified size. The manual names the approved cylinder, and using anything outside that range can void warranties or create a genuine safety problem.
- Measure the cabinet or propane compartment. Height, width, and depth — the 20 lb tank is only the default because it fits most carts, not because it fits all of them.
- Match the valve, fitting, and orientation. A cylinder should be used only in the position the appliance manual or product listing specifies.
As a working rule, portable grills generally run on 1–40 lb cylinders, while full-size freestanding grills are typically paired with 20–60 lb cylinders depending on what the maker recommends. If you’re replacing a worn-out tank and want tested options rather than a spec sheet, the top-rated BBQ propane cylinders our team compared side by side can shortcut that decision.
How Long Does A 20 lb Tank Actually Last?
A 20 lb cylinder delivers roughly 18–20 hours of grilling, though that’s a usage estimate rather than a specification — burner count and heat level move it a lot.
The “20 lb” label also causes real confusion. It refers to propane capacity, not the cylinder’s weight. A full 20 lb tank holds about 4.6–4.7 gallons of propane, and the steel shell adds several more pounds on top of that. So the number on the collar is not what the tank weighs on a scale.
That distinction powers the one genuinely useful trick here: every cylinder carries a tare weight (TW) marking. Weigh the tank, subtract the tare weight, and the remainder is your remaining propane. No gauge, no guessing, no shaking the tank in the driveway.
Sizing and dimensions aren’t standardized across sellers either. The grill maker’s approved cylinder and the cylinder’s own marked specifications control the choice — not a chart, including this one. Superior Plus Propane’s guidance carries the same caution, and you can read more in Superior Plus Propane’s tank information, which explains why you should always verify against the specific cylinder in front of you.
FAQs
Can I put a 30 lb tank on a grill designed for a 20 lb tank?
Only if the grill’s manufacturer approves it. The extra height and weight can block lid clearance and stress the tank retention bracket, and an unapproved cylinder may void your warranty. Check the manual’s specified range before swapping up, and confirm the compartment physically closes with the hose connected.
Is a “20 lb” tank really 20 pounds?
No. The 20 lb figure is propane capacity, not total weight. A full cylinder holds about 4.6–4.7 gallons of propane, and the steel shell adds more pounds on top. Weigh the tank and subtract the TW marking on the collar to find your actual remaining propane.
Why do two 20 lb tanks measure differently?
Because cylinder dimensions aren’t perfectly standardized across manufacturers or sellers. AmeriGas, Ferrellgas, and Superior Plus Propane each list slightly different figures — 18 × 12 in versus 17.8 × 12.3 in, for instance. Treat any chart as a starting point and measure the actual cylinder.
References & Sources
- AmeriGas. “Propane Tank Sizes” Lists standard cylinder dimensions and capacities, including the 20 lb grill tank.
- Ferrellgas. “Understanding the Various Propane Tank Sizes” Covers portable cylinder sizes and typical grilling uses.
- Superior Plus Propane. “Tank Information” Explains cylinder markings, tare weight, and verifying specifications.
