Ammo Can Dimensions: Sizes, Width, Heights & Diameters 2026
Ammo can dimensions vary widely from the compact 30 cal box at 10 inches (25.4 cm) long to the massive 81mm mortar can stretching over 21 inches (53.3 cm). These metal containers show up in military surplus stores, gun ranges, off-grid workshops, and survivalist gear setups worldwide. The standard 50 cal ammo can sits roughly as wide as a hardcover novel and as tall as a standard brick.
Whether you’re organizing your range gear, repurposing military surplus cans for storage, or sourcing the right container for a specific caliber, knowing exact ammo can dimensions gives you an instant reference point.
Standard Ammo Can Sizes
Military ammo cans follow strict specifications set by the U.S. Department of Defense. These specs ensure cans stack perfectly, seal airtight, and survive extreme conditions. The most common formats 30 cal, 50 cal, 40mm, and 81mm cover the needs of most shooters, collectors, and preppers.
Each can uses a rubber gasket lid that creates a weatherproof seal. This seal keeps moisture, dust, and air out protecting contents for decades. That is why surplus ammo cans command strong resale value even decades after manufacture.
Quick Reference Chart
| Can Type | Length | Width | Height | Common Use |
|---|---|---|---|---|
| 30 Cal | 10.0 in (25.4 cm) | 3.5 in (8.9 cm) | 7.0 in (17.8 cm) | .30 cal ammo, handgun rounds, small gear |
| 50 Cal | 11.5 in (29.2 cm) | 5.5 in (14.0 cm) | 7.25 in (18.4 cm) | .50 cal, rifle rounds, tools, survival kits |
| 40mm Grenade | 14.0 in (35.6 cm) | 7.5 in (19.1 cm) | 7.75 in (19.7 cm) | 40mm grenades, large gear, food storage |
| 81mm Mortar | 21.5 in (54.6 cm) | 10.75 in (27.3 cm) | 9.25 in (23.5 cm) | Mortar rounds, large tools, bulk storage |
All measurements represent exterior dimensions. Interior usable space is slightly smaller due to wall thickness of approximately 0.1 inches (2.5 mm).
30 Cal Ammo Can Dimensions
The 30 cal ammo can is the smallest and most portable standard military can. It originally stored M1919 .30 caliber machine gun belts for infantry use.
Exterior Dimensions:
- Length: 10.0 inches (25.4 cm / 254 mm)
- Width: 3.5 inches (8.9 cm / 89 mm)
- Height: 7.0 inches (17.8 cm / 178 mm)
Interior Dimensions:
- Length: 9.75 inches (24.8 cm)
- Width: 3.25 inches (8.3 cm)
- Height: 6.75 inches (17.1 cm)
The 30 cal can is roughly the same length as a standard school ruler and slightly taller than a large hardcover book. You can grip it comfortably with one hand using the folding steel handle on top.
Shooters use this can for 9mm, .45 ACP, .38 Special, .223, and .308 rifle rounds. It holds approximately 800 rounds of 9mm or 350 rounds of .223 Remington with room to spare. Survivalists and campers love it for its small footprint and easy portability.
The 30 cal can weighs about 5 pounds (2.3 kg) empty. Fully loaded with 9mm rounds, it tips the scale at roughly 17 to 20 pounds (7.7 to 9.1 kg). Its narrow 3.5-inch (8.9 cm) width allows two cans to sit side by side in most truck toolboxes.
50 Cal Ammo Can Dimensions
The 50 cal ammo can is the most recognized military surplus container in the world. Originally designed for M2 Browning .50 caliber machine gun ammunition, it became the universal storage solution for shooters and preppers everywhere.
Exterior Dimensions:
- Length: 11.5 inches (29.2 cm / 292 mm)
- Width: 5.5 inches (14.0 cm / 140 mm)
- Height: 7.25 inches (18.4 cm / 184 mm)
Interior Dimensions:
- Length: 11.0 inches (27.9 cm)
- Width: 5.0 inches (12.7 cm)
- Height: 7.0 inches (17.8 cm)
The 50 cal can is roughly the size of a standard shoebox wide enough to lay a standard brick flat inside with a little room around it. Its 5.5-inch (14 cm) width is the key difference from the narrower 30 cal can.
This can holds approximately 200 rounds of .50 BMG, 500 rounds of .308 Winchester, or 1,000+ rounds of 9mm. Military armorers, competitive shooters, and long-range rifle hunters all rely on it daily. Its 7.25-inch (18.4 cm) height allows it to stack two cans high in a standard military storage locker.
The 50 cal can weighs 7 pounds (3.2 kg) empty. Four stacked 50 cal cans fit neatly inside a standard military footlocker. You will find this format at virtually every gun range, gun show, and military surplus store in North America.
40mm Grenade Can Dimensions
The 40mm grenade can stores M203 and M79 grenade launcher rounds. It is significantly wider and longer than the 50 cal can, which gives it impressive multi-purpose storage capacity for civilian users.
Exterior Dimensions:
- Length: 14.0 inches (35.6 cm / 356 mm)
- Width: 7.5 inches (19.1 cm / 191 mm)
- Height: 7.75 inches (19.7 cm / 197 mm)
Interior Dimensions:
- Length: 13.5 inches (34.3 cm)
- Width: 7.0 inches (17.8 cm)
- Height: 7.5 inches (19.1 cm)
The 40mm can is roughly the same length as a standard laptop computer. Its 7.5-inch (19.1 cm) width makes it nearly twice as wide as the 30 cal can. You can lay a standard tablet flat inside the interior with plenty of vertical clearance.
Civilian users repurpose this can for first aid kits, tool sets, emergency food storage, and electronics. Its large interior volume of approximately 708 cubic inches (11.6 liters) makes it one of the most useful surplus cans for off-grid preparedness. Camp cooks use it to store spice kits, cooking tools, and fuel canisters together in one sealed container.
The 40mm can weighs approximately 9 pounds (4.1 kg) empty. Its flat, wide base keeps it stable on uneven surfaces. Overlanding and off-road enthusiasts mount these cans to roof racks and rear bumper carriers using standard MOLLE or bolt-on brackets.
Giant Mortar Cans
Giant mortar cans represent the largest standard military ammo can format. They store large-caliber artillery and mortar rounds that would not fit in any smaller container. Civilian users prize them for bulk storage, workshop organization, and off-grid living setups.
These cans use the same rubber gasket lid system as smaller formats. That seal keeps contents dry and protected even in field conditions. The sheer size means you can store an entire emergency supply kit food, water purification, tools, and medical gear — inside a single can.
81mm Mortar Ammo Can Dimensions
The 81mm mortar ammo can is the largest commonly available military surplus ammo can. It stored M821 and M889 81mm mortar rounds for use with the M252 mortar system.
Exterior Dimensions:
- Length: 21.5 inches (54.6 cm / 546 mm)
- Width: 10.75 inches (27.3 cm / 273 mm)
- Height: 9.25 inches (23.5 cm / 235 mm)
Interior Dimensions:
- Length: 21.0 inches (53.3 cm)
- Width: 10.25 inches (26.0 cm)
- Height: 9.0 inches (22.9 cm)
The 81mm can is roughly the same length as a standard acoustic guitar body. Its 10.75-inch (27.3 cm) width means two 50 cal cans placed side by side would barely match it in width. The interior volume reaches approximately 1,935 cubic inches (31.7 liters) large enough to store a complete bug-out bag’s worth of supplies.
Preppers use this can for 72-hour emergency kits, bulk grain storage, or waterproof document archives. Homesteaders seal seeds, dried foods, and first aid supplies inside for long-term storage. The empty can weighs approximately 18 pounds (8.2 kg), so most users keep it stationary rather than carry it.
At 9.25 inches (23.5 cm) tall, the 81mm can sits shorter than it is wide. This low profile makes it easy to slide under a truck bed or workshop bench. Two 81mm cans stacked vertically reach just over 18.5 inches (47 cm) — slightly shorter than a standard kitchen countertop height.
Pro Tips
Use these practical tips to get the most from your ammo cans whether for ammo storage, emergency prep, or everyday organization.
🔒 Check the Gasket First Always inspect the rubber lid gasket before relying on any surplus can for moisture-sensitive storage. A cracked or flat gasket breaks the airtight seal. Replacement gaskets cost under $5 (about 4.5 cm worth of rubber tubing) and restore the seal completely.
📐 Measure Your Space Before You Buy A 50 cal can at 11.5 inches (29.2 cm) long fits most truck toolboxes. An 81mm can at 21.5 inches (54.6 cm) long does not. Measure your shelf, rack, or vehicle storage space before purchasing large format cans.
🧲 Label Every Can Clearly Military cans look identical once stacked. Use a paint pen or adhesive label on the front face to mark contents, caliber, round count, and purchase date. This saves time at the range and prevents dangerous mix-ups.
⚖️ Know Your Weight Limits A fully loaded 50 cal can of .50 BMG rounds weighs approximately 50 pounds (22.7 kg). Stack no more than two loaded large cans on wooden shelving without reinforcement. Steel shelving handles stacked ammo cans without concern.
🌡️ Store in a Climate-Stable Location Ammo degrades faster in extreme heat and humidity. Store sealed cans in a location that stays between 55°F and 85°F (12.8°C and 29.4°C). A sealed 50 cal can in stable conditions protects ammunition for 10 years or longer.
🔧 Repurpose with Foam Inserts Pick-and-pluck foam inserts cut exactly to your can’s interior dimensions transform ammo cans into protective cases for cameras, electronics, or handguns. A 50 cal interior of 11.0 x 5.0 x 7.0 inches (27.9 x 12.7 x 17.8 cm) fits most compact handguns with accessories.
Read: Pokémon Card Dimensions
Read: Standard Chips Bag Size
Read: Magazine Dimensions
Read: Wheelchair Dimensions
Read: Coffee Can Dimensions
Read: Stair Dimensions
Frequently Asked Questions
What are the dimensions of a standard 50 cal ammo can?
A standard 50 cal ammo can measures 11.5 inches (29.2 cm) long, 5.5 inches (14.0 cm) wide, and 7.25 inches (18.4 cm) tall on the exterior. Interior usable space is approximately 11.0 x 5.0 x 7.0 inches (27.9 x 12.7 x 17.8 cm). It weighs about 7 pounds (3.2 kg) empty.
How big is a 30 cal ammo can?
A 30 cal ammo can measures 10.0 inches (25.4 cm) long, 3.5 inches (8.9 cm) wide, and 7.0 inches (17.8 cm) tall. It is the smallest standard military surplus can format. Its narrow 3.5-inch (8.9 cm) width makes it easy to fit two side by side in tight spaces.
What fits inside an 81mm mortar ammo can?
The 81mm mortar can has an interior volume of approximately 1,935 cubic inches (31.7 liters). You can fit a complete emergency preparedness kit, bulk dry food storage, or large tool sets inside. Its interior measures roughly 21.0 x 10.25 x 9.0 inches (53.3 x 26.0 x 22.9 cm).
How many rounds does a 50 cal ammo can hold?
A 50 cal ammo can holds approximately 200 rounds of .50 BMG, 500 rounds of .308 Winchester, or over 1,000 rounds of 9mm. Capacity varies by round size, packaging, and whether you use stripper clips or loose rounds. Most shooters load to about 80% capacity to avoid jamming the lid gasket.
Are all ammo cans waterproof?
Military surplus ammo cans with an intact rubber gasket are effectively waterproof and airtight. A properly sealed 50 cal can submerged in shallow water will keep contents dry. Always test the gasket seal before trusting a used surplus can with moisture-sensitive contents replace cracked gaskets immediately.
What is the difference between a 30 cal and 50 cal ammo can?
The 50 cal can is 1.5 inches (3.8 cm) longer, 2.0 inches (5.1 cm) wider, and 0.25 inches (6.4 mm) taller than the 30 cal can. That extra width gives the 50 cal significantly more interior volume. The 50 cal weighs 2 pounds (0.9 kg) more empty and handles a much wider range of storage tasks.
Conclusion
Ammo can dimensions span a precise range from the portable 30 cal at 10.0 x 3.5 x 7.0 inches (25.4 x 8.9 x 17.8 cm) to the massive 81mm mortar can at 21.5 x 10.75 x 9.25 inches (54.6 x 27.3 x 23.5 cm). The iconic 50 cal can at 11.5 x 5.5 x 7.25 inches (29.2 x 14.0 x 18.4 cm) remains the most widely used format across shooting sports, military surplus, and emergency preparedness in 2026.
Now that you know exact ammo can dimensions, you can choose the right size for your caliber, plan your storage space accurately, and repurpose surplus cans with confidence.
