REFERENCE
Gas cylinder sizes chart
The Airgas size 300 high-pressure cylinder, which Praxair calls a T and Matheson a 1L, is about 9 in across and 55 in tall. Linde lists its T at 335 cu ft of argon at 2,640 psig, and its K (Airgas 200, about 9 x 51 in) at 248 cu ft at 2,200 psig. Smaller welding sizes such as the Airgas 125, 80 and 40 are 7 in across and 43, 33 and 19 in tall. Filter the chart below by supplier, type or gas, and work out how much gas is left in yours.
Updated October 12, 2026
Sources: Airgas, Gas Cylinders brochure MCM-552 (2022); Airgas, Specialty Gas Cylinder Size Comparison Chart (catalog appendix); Nippon Sanso (Matheson), Common Industrial Cylinder Dimensions; Nippon Sanso (Matheson), Standard Gases Cylinder Chart; Linde Direct, gas pages for argon, nitrogen, oxygen, helium, hydrogen and carbon dioxide; General Air (Linde distributor, Colorado), Cylinder Size Chart 2021.
High-pressure cylinder sizes (Airgas)
| Airgas size | DOT spec | Diameter x height | Tare (avg) | Water capacity |
|---|---|---|---|---|
| 300 | 3AA2400 | 9 x 55 in | 137 lb | 49.8 L |
| 200 | 3AA2265, 3AA2015 | 9 x 51 in | 119 lb | 43.9 L |
| 125 | 3AA2265, 3AA2015 | 7 x 43 in | 62 lb | 22.6 L |
| 80 | 3AA2015 | 7 x 33 in | 57 lb | 15.9 L |
| 40 | 3AA2015 | 7 x 19 in | 26 lb | 7.4 L |
| 20 | 3AA2015 | 5.3 x 13.8 in | 11 lb | 3.6 L |
| E | 3AA2015 | 4 x 26 in | 14 lb | 4.5 L |
| 150A | 3AL2015 | 8 x 48 in | 48 lb | 29.5 L |
| 80A | 3AL2216 | 7 x 33 in | 32 lb | 15.8 L |
From Airgas brochure MCM-552 (2022). Nominal dimensions exclude valve and cap. Aluminum sizes end in A. Airgas prints the 200 and 125 DOT specs as one string, read here as 3AA2265 and 3AA2015.
Suppliers publish slightly different numbers for the same size, so this page keeps each supplier’s figures on their own rows. Airgas lists its 300 at 137 lb tare and 49.8 L water capacity; Nippon Sanso lists its 300 at 139 lb and 49 L. Nippon Sanso notes its tare includes the valve but not the cap, which it puts at 5 in long and 2 lb.
How much gas is in a T or K cylinder
| Gas | T (about 9 x 55 in) | K (about 9 x 51 in) |
|---|---|---|
| Argon | 335 cu ft at 2,640 psig | 248 cu ft at 2,200 psig |
| Nitrogen | 304 cu ft at 2,640 psig | 228 cu ft at 2,200 psig |
| Oxygen | 337 cu ft at 2,640 psig | 249 cu ft at 2,200 psig |
| Helium | 286 cu ft at 2,640 psig | 213 cu ft at 2,200 psig |
| Hydrogen | 261 cu ft at 2,400 psig | 196 cu ft at 2,000 psig |
Linde Direct gas pages, at 70 F. Linde also lists a K of carbon dioxide at 64 lb and a 4K of nitrogen at 430 cu ft at 4,500 psig.
Contents change with the gas and the fill pressure, not just the shell. Linde’s T holds 286 cu ft of helium but 335 cu ft of argon at the same 2,640 psig. Read the cylinder’s label for its actual contents.
Same cylinder, different names
| Approx. inches | Airgas | Praxair | Linde | Matheson | Air Liquide |
|---|---|---|---|---|---|
| 9 x 55 | 300 | T | 049 | 1L | 49 |
| 9 x 51 | 200 | K | 044 | 1A | 44 |
| 7 x 33 | 80 | Q | 016 | 2 | 16 |
| 7 x 19 | 35 | G | 007 | 3 | 7 |
| 2 x 12 | LB | LB | LBR | LB | LB |
| 4 x 26 | E | ANE | 005 | 3L | MEDE |
| 10 x 51 | 3HP | 6K | 485 | 1U | 44H |
| 9 x 51 | 2HP | 3K | - | 1H | 44H |
| 10 x 52 (aluminum) | 300A | - | - | - | AT |
| 8 x 48 (aluminum) | 150A | AS | A31 | 1R | 30AL |
| 7 x 33 (aluminum) | 80A | AQ | A16 | 2R | 22AL |
| 7 x 16 (aluminum) | 33A | AG | A07 | 3R | 7AL |
| 4.5 x 15 (aluminum) | 9A | - | - | - | 9AL |
Airgas Specialty Gas Cylinder Size Comparison Chart. Dimensions are approximate; a dash means no equivalent is listed. The Linde column is as Airgas lists it; Linde Direct’s own gas pages use the T and K names.
How much gas is left
For compressed gases such as argon, nitrogen, oxygen, helium and most mixes, the gauge pressure falls roughly in step with the contents. A Linde T of argon, 335 cu ft at 2,640 psig, reading 1,320 psig has about 167.5 cu ft left. That is an approximation: it assumes the same temperature as the fill and ignores how real gases compress.
Liquefied gases such as carbon dioxide and propane are different. Airgas defines a liquefied compressed gas as one that is partly liquid in the cylinder at 70 F, and suppliers fill them by weight: Linde sells CO2 cylinders by the pound, and Praxair’s CO2 filling procedure ends on a scale. While liquid is left, the gauge shows vapor pressure rather than how much remains, so weigh the cylinder and subtract the tare weight stamped on it. Acetylene is dissolved in a solvent inside its cylinder; ask your supplier how to weigh it.
Propane and acetylene cylinders
| Airgas propane size | Diameter x height | Propane (max) | Gallons |
|---|---|---|---|
| PR 20 | 12 x 18 in | 17 lb | 4 gal |
| PR 33 | 12.25 x 28.5 in | 32 lb | 8 gal |
| PR 40 | 12 x 29 in | 38 lb | 9 gal |
| PR 60 | 12 x 40 in | 57 lb | 14 gal |
| PR 100 | 14.75 x 48.5 in | 95 lb | 22 gal |
| PR 420 | 30 x 52.5 in | 400 lb | 95 gal |
Airgas MCM-552, low-pressure cylinders. Dimensions are width x height as printed.
| Airgas acetylene size | Diameter x height | Acetylene |
|---|---|---|
| AC MC | 3.8 x 15.1 in | 10 cu ft |
| AC B | 6 x 23.1 in | 40 cu ft |
| AC 3 | 7.2 x 31.3 in | 75 cu ft |
| AC 4 | 8 x 39.1 in | 145 cu ft |
| AC 5 | 12 x 46.7 in | 397 cu ft |
Airgas MCM-552. Airgas prints these figures under an Internal Volume heading.
Terms on a cylinder spec sheet
Tare weight: the empty cylinder’s weight, used to work out contents by weight. Check whether the figure includes the valve.
Water capacity: the inside volume, measured as the water it holds, in liters or pounds.
Service pressure: the pressure rating of the cylinder. In the Nippon Sanso chart the number after the DOT specification matches it, for example 3AA2265 and 2,265 psig.
DOT specification: the federal design the cylinder is built to. In the Airgas brochure, most steel high-pressure cylinders are 3AA, the lecture bottles 3E, the aluminum ones 3AL, the propane cylinders 4B, 4BA, 4BW or 4E, and the acetylene cylinders DOT-8 or 8AL.
Common questions
What size cylinder do I have?
Measure the diameter and the height without the valve and cap, then find the closest row. A 9 x 55 in steel cylinder is a 300 or T; a 9 x 51 in is a 200 or K; 7 x 33 in is an 80 or Q.
Why does my supplier’s chart show different numbers?
Fill pressures, cylinder makers and rounding differ. Every row here links to the supplier sheet it came from; your supplier’s figures and the label on your cylinder govern.
Limits
This chart repeats published supplier figures, which the suppliers themselves call approximate. It is not a guide to filling, transporting or handling cylinders. For shipping cylinders as hazmat, see the DOT hazard classes and placard lookup.
Sources
Airgas, Specialty Gas Cylinder Size Comparison Chart (catalog appendix)
Nippon Sanso (Matheson), Common Industrial Cylinder Dimensions
Linde Direct, gas pages for argon, nitrogen, oxygen, helium, hydrogen and carbon dioxide
General Air (Linde distributor, Colorado), Cylinder Size Chart 2021
Asia Industrial Gases Association, Filling of Carbon Dioxide Cylinders (Praxair Thailand, 2007)
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