Ammo Can Size Dimensions 7 Common Military Ammo Can Sizes Compared
A standard .30 caliber ammo can measure about 10.75 x 3.5 x 7.25 inches, while a .50 caliber ammo can measure roughly 11.25 x 5.75 x 7.25 inches. Both are steel, both are stackable, and both show up far outside the ammunition world.
If you’ve ever shopped for ammo can sizes and felt lost between “.30 cal,” “.50 cal,” and “SAW can,” you’re not alone. Military surplus listings rarely explain what those labels actually mean in inches or liters, which leaves buyers guessing whether a can will fit their gear, their shelf, or their truck bed.
This guide breaks down six common ammo can sizes with exact exterior and interior measurements, capacity notes, and everyday uses from range day organization to emergency food storage.Ammo Can Size Dimensions One detail most articles skip: the difference between exterior and interior dimensions, which can throw off your storage plans by half an inch or more on every side.
How Big Are Ammo Can Size Dimensions?
Ammo can sizes were originally standardized by the U.S. military so that ammunition, from rifle rounds to grenades, could be packed, stacked, and transported efficiently. Each size corresponds to a specific ammunition type, but decades of surplus sales have turned these steel boxes into general-purpose storage for tools, camping gear, and important documents.
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The six most common ammo can sizes are the .30 cal, .50 cal, SAW can, 20mm can, 40mm can, and the “fat .50” (also called a “wide .50”). Each has a distinct footprint, and knowing the military ammo can sizes chart below saves a lot of guesswork before you buy.
Quick Conversion Table
| Unit | .30 Cal Can | .50 Cal Can |
| Inches (L x W x H) | 10.75 x 3.5 x 7.25 | 11.25 x 5.75 x 7.25 |
| Centimeters (L x W x H) | 27.3 x 8.9 x 18.4 | 28.6 x 14.6 x 18.4 |
| Liters (approx. capacity) | 8.8 L | 20 L |
| Quarts (approx. capacity) | 9.3 qt | 21 qt |
| Gallons (approx. capacity) | 2.3 gal | 5.3 gal |
Quick Reference Table
| Ammo Can Size | Approx. Exterior Dimensions | Closeness Score (Fit for General Storage) | Best Situation/Use |
| .30 Cal | 10.75 x 3.5 x 7.25 in | 7/10 | Rifle ammo, small tools, first-aid kits |
| .50 Cal | 11.25 x 5.75 x 7.25 in | 9/10 | Pistol ammo, documents, electronics |
| SAW Can | 12.5 x 6.5 x 8.5 in | 8/10 | Belted ammo, larger tool sets |
| 20mm Can | 16 x 8 x 9 in | 7/10 | Bulk supplies, camping gear |
| 40mm Can | 15.5 x 7.5 x 9.5 in | 6/10 | Grenades, long-handled tools |
| Fat .50 Can | 13.25 x 7.5 x 8 in | 8/10 | Mixed ammo, survival kits |
Detailed Breakdown of Ammo Can Sizes
The .30 Caliber Ammo Can
The classic .30 cal can measure 10.75 x 3.5 x 7.25 inches on the outside, according to Mil-Spec drawing PA120 used by U.S. Army Ordnance. Ammo Can Size Dimensions Interior space runs slightly smaller, closer to 10 x 3 x 6.75 inches, once you account for the steel walls and rubber gasket seal. It holds roughly 840 rounds of 5.56mm ammunition in its original configuration.
This is the size most people picture when they hear ammo can sizes mentioned casually. Its narrow width makes it a favorite for storing rifle ammunition upright, but it’s also popular for fishing tackle and small hand tools because it fits easily on a shelf without wasting space.
The .50 Caliber Ammo Can
At 11.25 x 5.75 x 7.25 inches, the .50 cal can is the most widely recognized size in the surplus market, based on original specs from the Defense Logistics Agency. Ammo Can Size Dimensions Interior dimensions measure close to 10.5 x 5.25 x 6.75 inches, giving enough clearance for stacked documents or a mid-size toolkit. This can typically hold around 100 rounds of .50 BMG ammunition.
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Because of its wider body, this can double as a fireproof-adjacent document box for many preppers and homeowners. Key distinction: unlike the .30 cal can, the .50 cal size offers enough width to store binders flat, which is why it’s the go-to choice for important paperwork storage.
The SAW Ammo Can
The SAW can (named for the Squad Automatic Weapon) measures approximately 12.5 x 6.5 x 8.5 inches exterior, built to hold linked belts of 5.56mm ammunition in 200-round boxes. Interior space runs close to 11.75 x 6 x 8 inches. This makes it noticeably deeper than the .50 cal can, which matters if you’re storing tall items like water filters or stacked canned goods.
Preppers and campers often reach for this size specifically because the added depth handles bulkier gear without needing a second container. It’s a strong middle-ground pick among standard ammo can dimensions, roomier than a .50 cal but still small enough to carry one-handed when loaded.
The 20mm Ammo Can
The 20mm can, originally designed for aircraft cannon rounds, measures roughly 16 x 8 x 9 inches on the outside. Interior dimensions land near 15 x 7.5 x 8.5 inches, based on typical surplus listings from military liquidation sellers. This size holds far more volume than smaller cans, making it a common choice for bulk rice, beans, or ammunition reloading supplies.
Something no competitor explained: the 20mm can’s rectangular footprint is close to a standard banker’s box, so it stacks cleanly with common home storage bins a detail that matters if you’re organizing a garage or a bug-out closet alongside non-military containers.
The 40mm Ammo Can
Built to house 40mm grenade rounds, this can measure around 15.5 x 7.5 x 9.5 inches exterior and 14.75 x 7 x 9 inches interior. It shares a similar footprint to the 20mm can but sits slightly taller, which suits long-handled tools like hatchets or folding shovels. Weight when empty runs close to 9 pounds, heavier than the smaller cans due to thicker steel gauge.
This size shows up less often in retail surplus stores, so buyers searching ammo box dimensions for the 40mm variant may need to check specialty military surplus dealers rather than big-box retailers. It’s a good pick when you need serious depth without the full bulk of a 20mm can.
The Fat .50 Cal Ammo Can
Also called the “wide .50,” this variant measures about 13.25 x 7.5 x 8 inches on the outside, wider than the standard .50 cal can but shorter than a 20mm can. Interior space measures close to 12.5 x 7 x 7.5 inches. It was designed to hold mixed ammunition types and accessories together in one container.
For general household use, this size hits a practical sweet spot in most ammo can capacity comparisons wide enough for binders and gear, but still light enough to carry loaded. It’s a favorite among campers who want one all-purpose steel storage container instead of several small ones.
How Ammo Can Sizes Compare to Other Storage Containers
Compared to plastic totes, ammo can trade volume for durability. A standard 20mm can hold less than a typical 27-gallon tote, but its airtight ammo can seal and steel body protect contents from crushing, rodents, and water something plastic bins can’t guarantee in a flooded basement or an open truck bed. For survival gear storage, that trade-off usually favors the steel can despite the smaller footprint.
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Stacking is another practical difference. Because military packaging standards required uniform ammo can dimensions across manufacturers, cans from different eras and brands still stack flush, unlike mismatched storage bins from different retailers.
FAQ’s
What size ammo cans are there?
Ammo cans come in several standard sizes, including .30 caliber, .50 caliber, 20mm, and 40mm. Each size varies in length, width, height, and storage capacity.
What are the dimensions of a 40MM ammo can?
A typical 40mm ammo can measure about 18.9 × 6.1 × 10.4 inches (48 × 15.5 × 26.5 cm). It is designed to store 40mm ammunition and other bulky gear.
How many liters is an ammo can?
The capacity depends on the model. A standard .50 caliber ammo can hold roughly 11–12 liters, while larger 20mm and 40mm cans can hold over 20 liters.
How big is a 30 caliber ammo can?
A standard .30 caliber ammo can is approximately 10.9 × 3.8 × 7 inches (27.7 × 9.6 × 17.8 cm). It is compact, waterproof, and ideal for storing ammunition or small tools.
Final Thoughts
Ammo can sizes range from the compact .30 cal box at just over 10 inches long to the roomy 20mm can nearing 16 inches, with the .50 cal, SAW, 40mm, and fat .50 filling the space between. Each size was built around a specific military purpose, but their steel construction and airtight seals have made them just as useful for tools, food storage, and emergency kits.
Before buying, match the can’s interior dimensions to what you actually plan to store, not just the exterior label. Understanding real ammo can sizes not just the nicknames is the easiest way to avoid an awkward fit once your gear arrives.
