Comparing Moving Box Sizes, Units and Suitable Contents

There is no single universal moving box standard. US suppliers do, however, tend to sell the same small, medium and large boxes, labeled by nominal volume in cubic feet. The most commonly listed sizes are a 1.5 cu ft small box of about 16 x 12 x 12 inches (roughly 41 x 30 x 30 cm), a 3.0 cu ft medium box of about 18 x 18 x 16 inches (roughly 46 x 46 x 41 cm), and a 4.5 cu ft large box of about 18 x 18 x 24 inches (roughly 46 x 46 x 61 cm). A 6.1 cu ft extra-large box is also widely listed. Exact dimensions differ between suppliers, so check the measurements of the specific box you are buying against the items you need to pack.

Common moving box sizes in inches, centimeters and liters

The table below collects figures that moving companies and box sellers commonly publish. The centimeter and liter values are direct conversions of those published figures and are rounded. They are not measurements of any particular product.

Size | Nominal volume | Listed dimensions (in) | Approx. dimensions (cm) | Approx. volume (L)

Small | 1.5 cu ft | 16 x 12 x 12, also listed as 16 x 12.5 x 12.5 | 40.6 x 30.5 x 30.5, or 40.6 x 31.8 x 31.8 | 42.5

Medium | 3.0 cu ft | 18 x 18 x 16 | 45.7 x 45.7 x 40.6 | 85

Large | 4.5 cu ft | 18 x 18 x 24 | 45.7 x 45.7 x 61.0 | 127

Extra-large | 6.1 cu ft | Not consistently given in the sources reviewed | Not available | 173

Some boxes are sold in metric sizes rather than converted inch sizes. For example, a supplier outside the US lists a 60 x 40 x 40 cm moving box. That box works out to 96 liters, or about 3.4 cu ft, which places it between the US medium and large sizes. It does not match either one.

Why the numbers don't always line up

Size names and cubic-foot labels are nominal, so treat them as approximations.

• Small boxes vary the most. A 16 x 12 x 12 inch box works out to about 1.33 cu ft, and a 16 x 12.5 x 12.5 inch box to about 1.45 cu ft. Both are sold as "1.5 cu ft."
• The medium and large boxes in the table match their labels closely: 18 x 18 x 16 inches is 3.0 cu ft, and 18 x 18 x 24 inches is 4.5 cu ft.
• Some product listings give only partial or differently rounded dimensions, such as a small box listed at 16-3/8 inches or a medium at 18-1/8 inches. Two products called "medium" may not be the same box.
• The published figures reviewed here don't say whether they are inside or outside dimensions. If an item must fit with little clearance, ask the supplier for the interior measurements.

To convert a listing yourself, or to check its cubic-foot label, use these formulas:

centimeters  = inches x 2.54
cubic feet   = (length x width x height in inches) / 1728
liters       = cubic feet x 28.32
liters       = (length x width x height in cm) / 1000

What suits each box size

Moving guides consistently recommend the small box for books, canned goods, small tools and other heavy items. A full small box stays manageable even when its contents are dense.

The sources reviewed here give no comparably specific content lists for the medium, large and extra-large sizes. The guidance in the next list is therefore an editorial suggestion rather than a supplier requirement. It follows the same logic: the bigger the box, the lighter the contents should be per unit of volume.

• Small (about 41 x 30 x 30 cm): books, canned goods, small tools and other dense items. This size is recommended in the supplied sources.
• Medium (about 46 x 46 x 41 cm): mixed household items that are moderately heavy. This is an editorial suggestion.
• Large (about 46 x 46 x 61 cm): bulkier, lighter items. This is an editorial suggestion.
• Extra-large (6.1 cu ft): the lightest bulky items, if you use this size at all. This is an editorial suggestion; dimensions vary by supplier.

Weight limits are a property of each box's construction, not of its size name. Some guides attach a maximum load to the small box, but this article doesn't give a universal figure. Check the load rating printed on the box or stated by the supplier, and pack to what you can carry comfortably.

Choosing sizes for an apartment move

In an apartment, the right mix of box sizes depends on what you pack, how the boxes leave the building and where they wait in the meantime. The criteria below can help you decide. They are practical considerations, not rules drawn from the sources.

• Fit: measure your largest awkward items before you buy. Compare them against the specific supplier's dimensions, ideally the interior ones, rather than a size name.
• Effort and portability: dense items in small boxes keep each load manageable. This matters most when there are stairs, long hallways or a wait for a shared elevator.
• Access: if boxes must pass through narrow doorways, tight stair turns or a small elevator, a few large boxes may be harder to move than more medium ones.
• Staging space: boxes of the same footprint stack more neatly in a small room or hallway while you wait for moving day. The medium and large sizes in the table share an 18 x 18 inch base.
• Consistency: buying from one supplier makes it more likely that boxes with the same name actually match in size.

Gaps in the available information

This comparison is based on published supplier and moving-guide figures, not on measured products. It doesn't cover box quantities by home size, prices, availability, specialty boxes such as wardrobe or dish-pack cartons, or verified load ratings. For a specific purchase, rely on that product's stated dimensions and rating.