Have you ever seen those huge shipping containers being put on trucks or loading to boats and thought to yourself how big they actually are? The size of these metal boxes that get transported through highways and ports are indeed standardized, and their sizes along with their weight capacities can be quite varied. Although they might look identical from afar, there are certain standards set internationally that determine their size along with the amount of cargo they can carry and the transportation modes suitable for them.
Container Size Terminology Explained
Shipping container sizes follow a standardized naming system based on their dimensions. The entire global shipping industry runs on these standardized measurements to ensure containers can fit on ships, trucks, and trains worldwide.
Basic Size Designations
- Containers get named primarily by their length, with the two most common sizes being 20-foot and 40-foot containers. This length became so fundamental that shipping capacity worldwide gets measured in TEUs (Twenty-foot Equivalent Units). A 20-foot container equals 1 TEU, while a 40-foot container equals 2 TEUs.
- TEU (Twenty-foot Equivalent Unit) – The basic unit of container shipping capacity. One 20-foot container = 1 TEU.
- FEU (Forty-foot Equivalent Unit) – Equals 2 TEUs or one 40-foot container.
Height Classifications
- Container height gets classified into standard and high-cube variations:
- Standard Height – Typically 8’6″ (2.59m) tall
- High Cube (HC) – 9’6″ (2.89m) tall, providing an extra foot of vertical space
- Double Height – Specialized 17′ tall containers for oversized cargo
Width Standards
- Width remains highly standardized in the shipping world:
- Standard Width – 8′ (2.44m) for almost all containers worldwide
- Pallet-Wide – Slightly wider containers (2.50m) used mainly in European shipping
Naming Conventions
- Container naming follows specific patterns that tell you their specs at a glance:
- 20′ GP – 20-foot general purpose container
- 40′ HC – 40-foot high cube container
- 45′ HCPW – 45-foot high cube pallet wide container
Weight Terminology
- Tare Weight – Empty weight of the container itself
- Payload Capacity – Maximum cargo weight the container can legally hold
- Gross Weight – Combined weight of container and its cargo
- Maximum Gross Weight – The maximum allowed combined weight
Container Generation Markings
- Containers get marked with generation identifiers that determine stacking compatibility:
- Generation 1 – Older containers with 86,400 lb capacity.
- Generation 2 – Modern containers with 192,000 lb capacity, stackable 6-9 high.
| Container Type | External Dimensions (L×W×H) | Internal Dimensions (L×W×H) | Door Opening (W×H) | Tare Weight | Max Payload | Cubic Capacity | Common Uses |
|---|---|---|---|---|---|---|---|
| 20′ Standard | 20’×8’×8’6″ (6.06m×2.44m×2.59m) | 19’4″×7’8″×7’10” (5.89m×2.35m×2.39m) | 7’8″×7’6″ (2.34m×2.28m) | 2,300 kg | 28,200 kg | 33.2 m³ | Dense cargo, machinery, metals |
| 40′ Standard | 40’×8’×8’6″ (12.19m×2.44m×2.59m) | 39’5″×7’8″×7’10” (12.03m×2.35m×2.39m) | 7’8″×7’6″ (2.34m×2.28m) | 3,750 kg | 28,750 kg | 67.7 m³ | Bulk goods, furniture, general cargo |
| 40′ High Cube | 40’×8’×9’6″ (12.19m×2.44m×2.89m) | 39’5″×7’8″×8’10” (12.03m×2.35m×2.69m) | 7’8″×8’5″ (2.34m×2.56m) | 4,020 kg | 28,480 kg | 76.4 m³ | Lightweight voluminous cargo, retail goods |
| 45′ High Cube | 45’×8’×9’6″ (13.72m×2.44m×2.89m) | 44’4″×7’8″×8’10” (13.54m×2.35m×2.69m) | 7’8″×8’5″ (2.34m×2.56m) | 4,850 kg | 27,650 kg | 86.1 m³ | E-commerce shipments, large retail loads |
| 20′ Refrigerated | 20’×8’×8’6″ (6.06m×2.44m×2.59m) | 17’8″×7’5″×7’5″ (5.44m×2.29m×2.26m) | 7’5″×7’5″ (2.29m×2.26m) | 3,080 kg | 27,400 kg | 28.3 m³ | Perishable goods, pharmaceuticals |
| 40′ Refrigerated | 40’×8’×8’6″ (12.19m×2.44m×2.59m) | 37’9″×7’5″×7’5″ (11.56m×2.29m×2.26m) | 7’5″×7’5″ (2.29m×2.26m) | 4,800 kg | 27,700 kg | 58.4 m³ | Bulk temperature-controlled cargo |
| 40′ Refrigerated HC | 40’×8’×9’6″ (12.19m×2.44m×2.89m) | 37’9″×7’5″×8’5″ (11.56m×2.29m×2.56m) | 7’5″×8’5″ (2.29m×2.56m) | 4,900 kg | 27,580 kg | 67.3 m³ | Premium perishables, pharmaceuticals |
| 10′ Standard | 10’×8’×8’6″ (3.05m×2.44m×2.59m) | 9’3″×7’8″×7’10” (2.83m×2.35m×2.39m) | 7’8″×7’6″ (2.34m×2.28m) | 1,200 kg | 10,800 kg | 15.9 m³ | On-site storage, construction sites |
| 20′ Flat Rack | 20’×8’×8’6″ (6.06m×2.44m×2.59m) | 18’5″×7’3″×7’5″ (5.6m×2.2m×2.26m) | Open sides | 2,900 kg | 27,600 kg | N/A | Overwidth cargo, machinery, vehicles |
| 40′ Flat Rack | 40’×8’×8’6″ (12.19m×2.44m×2.59m) | 39’5″×7’1″×7’3″ (12.03m×2.16m×2.21m) | Open sides | 5,300 kg | 40,000 kg | N/A | Heavy equipment, construction materials |
| 20′ Open Top | 20’×8’×8’6″ (6.06m×2.44m×2.59m) | 19’4″×7’8″×7’10” (5.89m×2.35m×2.39m) | 7’8″×7’6″ (2.34m×2.28m) | 2,200 kg | 28,300 kg | 32.6 m³ | Tall cargo, top-loading requirements |
| 40′ Open Top | 40’×8’×8’6″ (12.19m×2.44m×2.59m) | 39’5″×7’8″×7’10” (12.03m×2.35m×2.39m) | 7’8″×7’6″ (2.34m×2.28m) | 3,900 kg | 28,600 kg | 66.7 m³ | Tall cargo, top-loading requirements |
| 20′ Tank | 20’×8’×8’6″ (6.06m×2.44m×2.59m) | Tank capacity varies | N/A | 3,070 kg | 27,430 kg | 21,000-26,000 L | Liquids, chemicals, food products |
| 40′ European PW | 40’×2.5m×2.6m | 39’5″×2.44m×2.38m | 2.43m×2.28m | 3,950 kg | 28,550 kg | 72 m³ | European pallets (fits 30 Euro pallets) |
| 45′ PW High Cube | 45’×2.5m×2.89m | 44’4″×2.44m×2.69m | 2.43m× nasa2.58m | 5,050 kg | 27,450 kg | 90 m³ | Maximum European pallet capacity (36) |
| 20′ Ventilated | 20’×8’×8’6″ (6.06m×2.44m×2.59m) | 19’4″×7’8″×7’10” (5.89m×2.35m×2.39m) | 7’8″×7’6″ (2.34m×2.28m) | 2,350 kg | 28,150 kg | 33.2 m³ | Coffee beans, cocoa, agricultural products |
| 53′ Domestic HC | 53’×8’6″×9’6″ (16.15m×2.59m×2.89m) | 52’6″×8’2″×8’10” (16m×2.5m×2.69m) | 8’2″×8’10” (2.5m×2.69m) | 7,800 kg | 25,700 kg | 107.1 m³ | North American domestic transport |
| 48′ Domestic | 48’×8’6″×9’6″ (14.63m×2.59m×2.89m) | 47’6″×8’2″×8’10” (14.48m×2.5m×2.69m) | 8’2″×8’10” (2.5m×2.69m) | 7,200 kg | 26,300 kg | 97.5 m³ | US domestic transport (less common now) |
Standard ISO Shipping Container Dimensions
ISO Codes
- ISO created a standardized identification system for container types:
- First character: Length (1 = 10′, 2 = 20′, 4 = 40′, etc.)
- Second character: Height and stacking capability
- Third character: Container type (G = general purpose, R = refrigerated, etc.)
- Fourth character: Features or ventilation detailsFor example, 22G1 designates a 20′ standard height general purpose container.
• ISO Standards Authority – Container dimensions globally follow the International Organization for Standardization (ISO) 668 standard, first introduced in 1968 and updated regularly since then This ensures worldwide intermodal compatibility across ships, trucks, and trains.• Length Designations – Standard ISO containers come primarily in these lengths:
- 20-foot (6.06 meters)
- 40-foot (12.19 meters)
- 45-foot (13.72 meters)
- 10-foot (3.05 meters), less common but still standardized
- 53-foot containers exist primarily for domestic transport in North America but don’t conform to ISO maritime standards
• Standard External Width – 8 feet (2.44 meters) is the universal external width for ISO containers worldwide
. This dimension remains consistent across almost all container types for global transport compatibility.• Standard External Heights:
- Standard height: 8 feet 6 inches (2.59 meters) * High cube (HC): 9 feet 6 inches (2.89 meters)
- Half height: 4 feet 3 inches (1.3 meters) for certain specialized cargo
• Dimensional Tolerances – ISO standards specify manufacturing tolerances of ±10mm for length and ±5mm for width and height. This precision ensures proper stacking and locking.• Door Opening Dimensions:
- Standard container door width: 7 feet 8 inches (2.34 meters)
- Standard container door height: 7 feet 6 inches (2.28 meters)
- High cube door height: 8 feet 5 inches (2.56 meters)
- Door openings are slightly smaller than the container’s internal dimensions to accommodate frame strength
• Internal Dimensions Reduction – Internal dimensions are reduced from external measurements due to:
- Wall thickness: Approximately 2 inches (5cm) total width reduction * Corrugation depth: 1-1.5 inches (25-38mm) per wall * Floor thickness: Approximately 6 inches (15cm) height reduction
- Ceiling structure: Approximately 4 inches (10cm) height reduction
• Standard 20ft Internal Dimensions:
- Length: 19 feet 4 inches (5.89 meters)
- Width: 7 feet 8 inches (2.35 meters)
- Height: 7 feet 10 inches (2.39 meters)
• Standard 40ft Internal Dimensions:
- Length: 39 feet 5 inches (12.03 meters)
- Width: 7 feet 8 inches (2.35 meters)
- Height: 7 feet 10 inches (2.39 meters)
• Corner Castings – Eight standardized corner fittings at every corner of the container follow ISO 1161 specifications:
- Dimensions: 178mm × 162mm × 118mm
- Aperture size: 66mm × 127mm oval openings
- These connect to twist locks during transport and stacking
• ISO Identification System – Each container carries a standardized identification code following ISO 6346:
- Four-letter owner code
- Six-digit serial number
- Check digit
- Optional type code indicating size and features
• Wall Construction – Container walls use corrugated steel panels with:
- Corrugation depth: 1-1.5 inches (25-38mm)
- Steel thickness: Typically 1.6-2.0mm for side walls
- This design maximizes strength while minimizing weight
• Floor Specifications:
- Standard thickness: 28mm hardwood plywood
- Floor strength rating: 5,460 kg per square meter (ISO 1496)
- Cross-members: 3-4 inches (75-100mm) I-beams spaced at 12-inch intervals
• Weight-Related Dimensions:
- Maximum gross weight: 30,480 kg for 20ft and 40ft containers
- Corner post strength: Designed to support up to 192,000 kg when stacked
- Floor point load capacity: 5,460 kg per square meter
- Racking test requirements: 150mm lateral displacement without permanent deformation
• Container Stacking Parameters:
- Corner post dimensions designed for 9-high stacking
- ISO 1496 requires testing for proper stacking capability
- Standardized corner castings position with ±5mm tolerance
• Twist Lock Engagement – Corner castings must accommodate standard twist locks with:
- Engagement depth: 32mm minimum
- Pull-out strength: 150 kN minimum in any direction
- This standardization ensures secure stacking on ships and secure fastening to transport equipment
• ISO Testing Requirements – Containers must pass dimensional verification tests:
- Diagonal measurement tolerance: ±10mm
- Frame squareness tolerance: ±5mm
- Door opening squareness: ±4mm
• Temperature Considerations – ISO standards account for thermal expansion:
- Dimension measurements specified at 20°C (68°F)
- Allowable dimensional changes from -40°C to +60°C calculated in specifications
• Lashing Points:
- Internal lashing points positioned at 1-meter intervals
- Standardized strength rating: 1,000 kg minimum
- External lashing points positioned according to ISO standards for secure transport
