Container sizes — quick reference
20ft Standard (interior)
19'4" × 7'8" × 7'10"
~160 sq ft floor area
40ft Standard (interior)
39'5" × 7'8" × 7'10"
~320 sq ft floor area
40ft High Cube (interior)
39'5" × 7'8" × 8'10"
~320 sq ft · 1ft taller
20ft max payload
~55,900 lbs
25,400 kg
40ft max payload
~58,600 lbs
26,600 kg
Standard door opening
7'8" × 7'5"
Width × Height (cargo doors)
In this guide
20ft Standard Container — Specifications
The 20ft container (ISO designation: 22G1) is the original intermodal shipping container size and the benchmark unit for cargo measurement worldwide — one 20ft container equals one TEU (Twenty-foot Equivalent Unit). It's the most widely available size on the used market and the most affordable entry point for container projects.
20ft Standard Container
ISO Type: 22G1 · 1 TEU40ft Standard Container — Specifications
The 40ft container (ISO designation: 42G1) is the most widely used container size for residential and commercial conversion projects. It provides approximately 320 square feet of floor area — equivalent to a generous studio apartment — and is available in large quantities in most US markets. The 40ft is the go-to choice for container home studios, offices, barns, and single-container builds.
40ft Standard Container
ISO Type: 42G1 · 2 TEU40ft High Cube Container — Specifications
The 40ft High Cube (ISO designation: 45G1) adds exactly one foot of height over the standard 40ft container. That extra foot — from 8'6" to 9'6" exterior, 7'10" to 8'10" interior — makes a significant difference in residential use. An 8'10" ceiling before insulation and framing yields a liveable ceiling height after finish work that a standard container cannot match. For any container home, office, or habitable space, the High Cube is the strongly recommended choice.
40ft High Cube Container
ISO Type: 45G1 · 2 TEUAll Sizes Compared
| Specification | 20ft Standard | 40ft Standard | 40ft High Cube |
|---|---|---|---|
| ISO designation | 22G1 | 42G1 | 45G1 |
| Exterior length | 20' 0" / 6.058 m | 40' 0" / 12.192 m | 40' 0" / 12.192 m |
| Exterior width | 8' 0" / 2.438 m | 8' 0" / 2.438 m | 8' 0" / 2.438 m |
| Exterior height | 8' 6" / 2.591 m | 8' 6" / 2.591 m | 9' 6" / 2.896 m |
| Interior length | 19' 4" / 5.898 m | 39' 5" / 12.032 m | 39' 5" / 12.032 m |
| Interior width | 7' 8" / 2.352 m | 7' 8" / 2.352 m | 7' 8" / 2.352 m |
| Interior height | 7' 10" / 2.385 m | 7' 10" / 2.385 m | 8' 10" / 2.698 m |
| Door width | 7' 8" / 2.340 m | 7' 8" / 2.340 m | 7' 8" / 2.340 m |
| Door height | 7' 5" / 2.278 m | 7' 5" / 2.278 m | 8' 5" / 2.585 m |
| Floor area | ~148 sq ft / 13.86 m² | ~301 sq ft / 28.3 m² | ~301 sq ft / 28.3 m² |
| Cubic volume | ~1,169 cu ft / 33.1 m³ | ~2,390 cu ft / 67.7 m³ | ~2,694 cu ft / 76.3 m³ |
| Tare weight | ~4,850 lbs / 2,200 kg | ~8,818 lbs / 4,000 kg | ~8,773 lbs / 3,980 kg |
| Max payload | ~61,289 lbs / 27,800 kg | ~58,379 lbs / 26,480 kg | ~58,424 lbs / 26,500 kg |
| Price (new) | $4,000–$6,000 | $5,500–$8,000 | $6,000–$9,000 |
| Price (used WWT) | $1,500–$3,500 | $2,000–$4,500 | $2,500–$5,500 |
| Best for | Storage, pool, gym, compact cabin | Home, office, barn | Home, office — residential preferred |
Dimension Diagrams
40ft Standard Container — Cross Section View
Cross-section view (end wall). Dimensions shown are nominal ISO standard. Actual measurements vary slightly between manufacturers and age of container.
Weight, Payload & Stacking Loads
| Weight specification | 20ft Standard | 40ft Standard | 40ft High Cube |
|---|---|---|---|
| Tare weight (container empty) | ~4,850 lbs / 2,200 kg | ~8,818 lbs / 4,000 kg | ~8,773 lbs / 3,980 kg |
| Maximum gross weight | 66,139 lbs / 30,480 kg | 67,197 lbs / 30,480 kg | 67,197 lbs / 30,480 kg |
| Maximum payload (cargo) | ~61,289 lbs / 27,800 kg | ~58,379 lbs / 26,480 kg | ~58,424 lbs / 26,500 kg |
| Stacking load (on corner posts) | ~192,000 lbs / 86,400 kg | ~192,000 lbs / 86,400 kg | ~192,000 lbs / 86,400 kg |
| Maximum stack height | 9 containers high | 9 containers high | 9 containers high |
| Roof live load (on corrugated roof) | ~600 lbs / 272 kg | ~600 lbs / 272 kg | ~600 lbs / 272 kg |
Critical: roof load vs corner post load
The ~600 lb roof live load is on the corrugated steel roof sheeting — the panels between the corner posts and top rails. The 192,000 lb stacking load is carried entirely by the four corner posts and their castings. When adding a canopy, solar panels, or a roof system to a container, all structural loads must transfer to the corner posts and top rails — never to the corrugated roof sheeting. See our A-frame roof case study for how this works in practice.
Usable Space After Insulation & Framing
The ISO interior dimensions above are the raw unfinished container interior. In any habitable conversion — home, office, cabin — you will lose space to insulation and framing on all four walls and the ceiling. The amount lost depends on the insulation method chosen.
| Insulation method | Thickness per wall | Width lost (both sides) | Usable width (40ft container) | Ceiling height lost |
|---|---|---|---|---|
| Closed-cell spray foam only | 2"–3" per wall | 4"–6" total | 7'2"–7'4" | 2"–3" |
| Spray foam + stud wall | 5.5"–7.5" per wall | 11"–15" total | 6'5"–6'9" | 4"–6" |
| Rigid board + stud wall | 5.5"–7.5" per wall | 11"–15" total | 6'5"–6'9" | 4"–6" |
Why High Cube matters for residential use
A 40ft standard container at 7'10" interior height loses 4"–6" to ceiling insulation and framing, finishing at approximately 7'4"–7'6" clear ceiling height — liveable but tight. A 40ft High Cube at 8'10" interior height finishes at approximately 8'4"–8'6" — a perceptible and meaningful improvement. For any full-time habitable conversion, the High Cube is worth the modest price premium.
Which Container Size for Which Use
20ft Container
Storage, workshop, pool, gym
The 20ft is ideal for storage buildings, container pools (20'×8' swim lane), home gyms, and compact workshops. Too small for most residential uses but perfectly sized for non-habitable applications. Most affordable entry point.
40ft Standard
Studio cabin, office, barn
The workhorse for container conversion projects. At ~320 sq ft it supports a complete studio or one-bedroom layout. Most abundant on the used market. Standard height works for agricultural and commercial use; for residential, consider High Cube.
40ft High Cube
Residential home, full-time living
The recommended choice for any habitable container — the extra foot of ceiling height after insulation and framing makes the difference between a space that feels tight and one that feels genuinely residential. Worth the modest premium for any home or office conversion.
2 × 40ft
Two-bedroom home, barn with bay
Two containers placed parallel (side-by-side) with shared wall removed creates a 16ft wide open-plan space. Placed end-to-end creates ~640 sq ft for a two-bedroom layout. The two-container parallel barn is the most popular agricultural configuration.
3 × 40ft
Full family home
Three containers provide ~960 sq ft — enough for a genuine 2–3 bedroom family home with separate social and sleeping zones. The minimum footprint for a full family residence. See our three-container house case study.
10ft Container
Small storage, niche uses
10ft containers (ISO type: 10G1) exist but are uncommon in the US market and rarely available used. Generally not recommended — limited availability means higher prices and fewer options. The 20ft is a better starting point for most small-footprint projects.
Frequently Asked Questions
What is the interior width of a shipping container?
The interior width of a standard shipping container — 20ft, 40ft, or 40ft High Cube — is 7 feet 8 inches (2.352 metres). This is the usable width before any insulation or framing is added. After closed-cell spray foam insulation on both walls (2"–3" per side), usable width drops to approximately 7'2"–7'4". After full stud-wall framing with insulation, usable width can be as low as 6'5"–6'9".
What is the difference between a 40ft standard and 40ft High Cube container?
The only difference is height. A 40ft standard container is 8'6" tall exterior (7'10" interior). A 40ft High Cube is 9'6" tall exterior (8'10" interior) — exactly one foot taller. Length, width, floor area, and payload capacity are essentially identical. The High Cube's taller door opening (8'5" vs 7'5") also allows taller cargo and easier move-in access for furniture and appliances.
How much does a shipping container weigh?
A 20ft container weighs approximately 4,850 lbs (2,200 kg) empty. A 40ft standard or High Cube container weighs approximately 8,800 lbs (4,000 kg) empty. When loaded to maximum capacity, both can reach approximately 66,000–67,000 lbs (30,480 kg) gross. For delivery planning, your transport company needs the tare weight — the empty container weight.
What is the floor area of a shipping container?
A 20ft container has approximately 148 square feet (13.86 m²) of floor area. A 40ft container (standard or High Cube) has approximately 301 square feet (28.3 m²). These are the raw interior dimensions — after framing and finished wall thickness, usable floor area will be slightly less. For comparison: a typical US studio apartment is 300–500 sq ft, making a single 40ft container comparable to a compact studio.
What is the door opening size on a shipping container?
Standard 20ft and 40ft containers have a cargo door opening of 7'8" wide by 7'5" tall (2.340 m × 2.278 m). This is the clear opening with both doors swung fully open. 40ft High Cube containers have the same width (7'8") but a taller opening at 8'5" (2.585 m). Note that a standard queen bed (60" wide) will fit through the standard cargo door opening, but a king bed (76" wide) will not without removing the frame.
How many shipping containers can be stacked?
Standard ISO shipping containers are rated to be stacked 9 high when loaded. The stacking load is carried entirely by the four corner posts and their corner castings — approximately 192,000 lbs (86,400 kg) per corner. The corrugated roof sheeting carries approximately 600 lbs of distributed live load. In container home and conversion projects, any roof additions or canopies must attach to the corner posts and top rails, never to the corrugated roof panels.
What is a TEU?
TEU stands for Twenty-foot Equivalent Unit — the standard unit of cargo measurement in the shipping industry. A 20ft container equals 1 TEU. A 40ft container equals 2 TEU. When shipping companies or ports talk about capacity in TEUs, they're counting how many 20ft containers worth of space they can handle.
Going to inspect a container?
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