Guide
Shipping container sizes: which one do I need?
Most people choose between a 20 ft and a 40 ft container, with a 10 ft box for small sites and a high cube when you need extra height. This guide gives the sizes, what fits in each, what the condition grades mean, and how to get the space ready for delivery.
Container sizes at a glance
All common containers are 8 feet wide on the outside. They differ in length and height. Inside sizes vary a little by manufacturer and by wall design, so treat the figures below as typical and ask the seller for the spec sheet of the unit you are buying.
| Size | Outside (L x W x H) | Inside (L x W x H) | Door opening (W x H) | Space inside |
|---|---|---|---|---|
| 10 ft | 10 ft x 8 ft x 8 ft 6 in | about 9 ft 3 in x 7 ft 8 in x 7 ft 10 in | about 7 ft 8 in x 7 ft 6 in | about 560 cu ft |
| 20 ft | 20 ft x 8 ft x 8 ft 6 in | about 19 ft 4 in x 7 ft 8 in x 7 ft 10 in | about 7 ft 8 in x 7 ft 6 in | about 1,170 cu ft |
| 40 ft | 40 ft x 8 ft x 8 ft 6 in | about 39 ft 6 in x 7 ft 8 in x 7 ft 10 in | about 7 ft 8 in x 7 ft 6 in | about 2,390 cu ft |
| 40 ft high cube | 40 ft x 8 ft x 9 ft 6 in | about 39 ft 6 in x 7 ft 8 in x 8 ft 10 in | about 7 ft 8 in x 8 ft 5 in | about 2,690 cu ft |
The 20 ft and 40 ft boxes are the standard shipping sizes, so they are the easiest to find. Most 10 ft containers are built for storage or cut down from a larger box. You may also see 20 ft high cubes and 45 ft containers, but they are less common and the longer ones are harder to deliver to a home.
What fits in each size
- 10 ft: tools, equipment and materials for a small jobsite, seasonal items, or a garden shed's worth of gear. It fits where a larger box will not.
- 20 ft: the furniture from a 1 to 2 bedroom home, about 10 standard pallets on the floor, or a typical car. Measure wide vehicles, mirrors included, against the door opening.
- 40 ft: the contents of a 3 to 4 bedroom home, farm or landscaping equipment, or about 20 standard pallets. It costs more to deliver and needs a lot more room for the truck.
- 40 ft high cube: the same floor as a 40 ft with about a foot more height. Pick it for tall items, tall shelving, or a container you plan to insulate and turn into an office or workshop, since insulation eats into the headroom.
A simple test: measure what you need to store, then add room for a walkway so you can reach the back. Not sure? The container size calculator suggests a size from what you are storing.
Condition grades: new, one-trip and used
Used containers are sold by grade. The names are trade terms, not a legal standard, and sellers use them a little differently, so read the description and ask for photos of the actual unit.
| Grade | What it usually means | Good for |
|---|---|---|
| New or one-trip | Built new and, for one-trip, carried one load of cargo before being sold. Clean paint, straight panels, tight doors. | Offices, homes and visible spots, or when you want the longest life |
| Cargo-worthy | Used, but in good enough shape to carry cargo by sea or rail. Often comes with a valid safety plate. | Shipping goods, or storage with a bit more assurance |
| Wind and water tight | Used. No holes, the doors close and seal, and it keeps weather out. Dents and surface rust are normal. Not certified for shipping. | Most storage on a farm, jobsite or business lot |
| As-is | May have holes, rust through or door problems. | Parts or projects only, after you inspect it |
Before you accept a used container, check it in daylight:
- Light test. Stand inside with the doors closed. Any light you see is a hole.
- Doors. Both should open, close and lock without a fight, and the rubber seals should be whole.
- Floor. Look for soft spots, holes and strong odors in the wood.
- Roof. Deep dents hold water and rust faster.
Delivery: space for a tilt-bed truck
Most containers arrive on a tilt-bed truck or trailer. The driver tilts the bed and pulls forward while the container slides off the back onto the ground. That needs a long, straight, clear run in front of the drop spot.
Sellers often ask for roughly 60 to 75 feet of straight clearance for a 20 ft container and roughly 100 to 120 feet for a 40 ft, with about 10 to 12 feet of width. The tilted bed rises high, so the space also needs to be clear of power lines and branches overhead. These are general figures: ask your seller what their truck needs.
- The ground has to hold a heavy truck. Soft lawns and wet fields can rut or trap it, so plan delivery for dry weather.
- Decide which way the doors should face before the truck arrives, so the container can be loaded the right way round.
- Walk the route: gates, tight turns, low wires and steep driveways all matter.
- Where a tilt-bed cannot fit, ask about a crane or forklift. It costs more but can reach tighter spots.
Getting the ground ready
A storage container does not need a full foundation, but it does need firm, level support. Steel boxes rest on their four corner castings, so that is where the support goes.
- Level it. A container that sits out of level twists slightly, and the doors may bind or not seal.
- Lift it off the dirt. Concrete blocks, railroad ties or a compacted gravel pad under the corners let air move underneath and slow rust on the floor frame.
- Plan for water. Do not set it in a low spot where rain collects.
- Leave room to open the doors. The two doors swing outward, so keep the area in front of them clear.
- Call 811 before you dig for footings or posts, so buried utility lines get marked.
Many cities and homeowner associations have rules for containers in yards and driveways, and some need a permit for a container that stays more than a few weeks. Check before delivery day.
Sources
- ISO 668, Series 1 freight containers: classification, dimensions and ratings
- Typical container manufacturer specifications for inside sizes, door openings and weights