Standard outside dimensions are a useful cross-check, not a substitute for measuring the real unit, attached hardware, and the coverage path.
A container top cover is much smaller than a full drape. Decide whether the tarp covers only the roof, reaches below the top rail, clears doors, or wraps stored equipment beside the container.
Standard outside dimensions
Hapag-Lloyd’s ISO-based specification lists 20-foot and 40-foot general-purpose containers at 8 ft wide and 8 ft 6 in high; high-cube height is 9 ft 6 in. Published metric lengths are 6,058 mm for 20 ft and 12,192 mm for 40 ft. Production tolerances and attached features still make field measurement necessary.
| Type | Nominal outside size | Use as |
|---|---|---|
| 20 ft standard | 20 × 8 × 8 ft 6 in | Planning check |
| 40 ft standard | 40 × 8 × 8 ft 6 in | Planning check |
| 40 ft high cube | 40 × 8 × 9 ft 6 in | Planning check |
Choose the coverage path
- Top only: roof length and width plus edge allowance.
- Top and partial sides: add the actual drop on both sides and both ends.
- Full drape: add two full height drops in each direction, plus working allowance.
Calculate, then check handling weight
For a rectangular full drape: tarp length = container length + two end drops + allowance; tarp width = container width + two side drops + allowance. A full 40-foot cover becomes very large, especially in high-mass fabric. Plan how it will be lifted and positioned before buying.
Doors, castings, and sharp corners
Record corner castings, locking bars, vents, door swing, roof repairs, and anything attached above the nominal envelope. Protect contact points and form drainage so water cannot collect in a broad unsupported pocket.
Important limits
A loose cover is not a structural roof, shipping-container repair, engineered wind restraint, or approved transport system. Do not climb on container roofs without a safe-access and fall-protection plan.
Dimensions source: Hapag-Lloyd Container Specification, based on ISO 668 dimensions.
How this guide was prepared
We separate geometry and unit conversions from product claims, use exact standards where available, and flag specifications that vary by manufacturer. See our editorial policy for the review process.