How many 18 × 18 × 16 in boxes fit in a 20ft container?
18 × 18 × 16 in boxes of 457 × 457 × 406 mm (also called 3 cubic foot boxes, medium moving boxes) in a 20-foot standard container (20GP) — inner dimensions 5,898 × 2,352 × 2,393 mm. Calculated by the Cubestow engine on 2026-09-08.
Boxes may be laid on any side. 89% of the space used, 5 layers high, about 4,900 kg (17% of payload). Open this load in the 3D planner →
Top view — floor layer (70 on the floor)
Side view — first row along the wall (5 layers)
The answer in detail
The "3.0 cubic foot" medium moving box (18 × 18 × 16 in) is the box most US movers use for the bulk of a household. Lying it on its side gains height in some containers, which is why the any-orientation count is higher.
The most common dry container for smaller export loads. Inner dimensions are typical for a steel ISO 20GP; individual boxes vary by a few centimetres, and the door opening (about 2,340 × 2,280 mm) is slightly smaller than the inside.
The simple grid estimate is 12 along the length × 5 across × 5 high = 300. The engine found 350 — 50 more than either uniform grid — by mixing orientations so that the leftover strip along the wall is used and by choosing the orientation that gives the most layers. The top view above shows the pattern.
Variants
| Loading rule | Fits | Layers | Volume used | Total weight |
|---|---|---|---|---|
| Boxes may be laid on any side (headline figure) | 350 | 5 | 89% | 4,900 kg (17% of payload) |
| Boxes kept this-side-up (turned on the floor plane only) | 300 | 5 | 77% | 4,200 kg (15% of payload) |
How many 20ft containers for a given order?
| 18 × 18 × 16 in boxes | 100 | 250 | 500 | 1,000 | 2,500 | 5,000 |
|---|---|---|---|---|---|---|
| 20ft containers needed | 1 | 1 | 2 | 3 | 8 | 15 |
| Last one filled to | 29% | 71% | 43% | 86% | 14% | 29% |
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Frequently asked
How many 18 × 18 × 16 in boxes fit in a 20ft container?
350 18 × 18 × 16 in boxes of 457 × 457 × 406 mm fit in a 20ft container (inner dimensions 5,898 × 2,352 × 2,393 mm), boxes may be laid on any side. That uses 89% of the 33.2 m³ available and weighs about 4,900 kg.
What are the inner dimensions of a 20ft container?
Typical inner dimensions are 5,898 mm long, 2,352 mm wide and 2,393 mm high (232.2 × 92.6 × 94.2 in), giving 33.2 m³ of space and a rated payload of about 28,200 kg. Individual units vary by a few centimetres, so check the actual box for tight loads.
How much does a full load of 18 × 18 × 16 in boxes weigh?
350 × 14 kg ≈ 4,900 kg, which is 17% of the 28,200 kg payload — so this load is limited by space, not weight.
How was this number calculated?
By running the Cubestow 3D load-planning engine on the exact dimensions above, allowing all six orientations, stacking with at least 80% base support and the container's payload limit, then re-validating the plan for overlaps, support and weight. Real loads leave room for dunnage, door clearance and uneven cartons, so treat the figure as the practical maximum.