15 Gallon Drum Dimensions | Real Sizes By Drum Type

A standard 15-gallon drum measures roughly 14 to 15 inches in diameter and 26 to 27.5 inches tall, though exact size depends on the material and lid style.

If you’re planning storage space, building a rack, or calculating shipping costs, the exact dimensions of a 15-gallon drum matter more than you’d think. A steel tight-head drum and a plastic open-head drum with the same 15-gallon rating can differ by over two inches in height, which is plenty to ruin a storage plan. Here’s what manufacturers actually publish, and why those numbers vary.

The Short Range: What Most 15-Gallon Drums Measure

Across current manufacturer spec sheets, most 15-gallon drums fall within a consistent band. The diameter sits between 14 and 15 inches, and the height lands between 26 and 27.5 inches. That’s the safe planning range if you haven’t picked a specific model yet.

Within that band, the material and closure type shift the numbers. Plastic closed-head models tend toward the middle of the range, while open-head plastic drums run taller, and tight-head steel drums run shorter.

Manufacturer Specs: Steel vs. Plastic, Open vs. Tight Head

The differences between drum types are significant enough that you shouldn’t assume one size fits all. Three published spec sheets show the pattern clearly.

Why 15-Gallon Drums Aren’t All The Same Size

Three factors explain most of the variation between models: material, head style, and how the manufacturer measures the drum.

Material Changes The Profile

Steel drums are drawn from sheet metal and tend to have thinner walls. The Rahway steel model uses 0.8 mm steel and comes in at 25 1/2 inches tall. Plastic drums are molded with thicker walls — Pipeline’s closed-head plastic drum is 1.8 mm thick — and that added wall thickness pushes the outside height up to 26 1/4 inches.

Open-Head Drums Run Taller

An open-head drum has a removable lid, and the latching ring adds height. Pipeline’s open-head plastic drum measures 27 1/2 inches tall for the drum alone, and 27 3/4 inches with the lid in place. That’s more than two full inches taller than the tight-head steel drum for the same 15-gallon capacity.

Diameter Is Measured In Three Different Places

Manufacturers publish outside diameter, inside diameter, and sometimes the opening diameter separately. The Rahway steel drum lists an outside diameter of 14 13/16 inches and an inside diameter of 13 15/16 inches. Pipeline’s open-head plastic drum lists 14 7/8 inches at the lid, 14 1/2 inches at the opening, and 12 3/4 inches at the bottom. Planning around the wrong figure leads to racks that don’t fit or lids that won’t clear.

Capacity, Fittings, And The UN Mark

Rated capacity and actual usable volume aren’t always identical. Pipeline’s spec sheet lists the closed-head plastic drum at 57 liters (15 gallons) nominal, but notes a larger overflow volume. That means you can fill past the rated line in practice, though doing so may complicate stacking or shipping.

Fittings also vary by model. The Pipeline plastic drums offer 2-inch and 3/4-inch bung openings.

For anything involving shipping or regulated materials, check the UN/DOT mark stamped on the actual drum. Published examples include 1H1/Y1.8/100 for the closed-head plastic drum and 1H2/Y105/S for the open-head model. These markings certify the drum’s performance rating for transport — they aren’t universal across brands.

Planning Around A 15-Gallon Drum

For most storage and racking plans, budgeting for a 15-gallon drum at about 15 inches in diameter and 28 inches in height gives you clearance for nearly any model, including the open-head plastic drums that run tallest. If you’re working with tight vertical space, a tight-head steel drum at 26 inches offers the shortest option.

Before you buy, confirm the exact outside dimensions of the specific model — that’s the figure that determines shelf spacing and crate fit. And if you’re comparing options for a project, the tested picks in our roundup of the best 15-gallon drums show what’s worth considering.