Intermodal Shipping Containers

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Standard ISO ocean freight containers are engineered under ISO 668 and ISO 1496 into 20-foot and 40-foot standardized modular lengths with 8-foot widths and 8'6" standard or 9'6" High Cube heights. Equipped with ISO corner castings, they enable seamless transfer across cargo ships, trains, and semi-trucks.

Source: ISO 668:2020 Series 1 freight containers / ISO 1496-1 Specifications · Last reviewed Aug 28, 2026

Specs

Governing Standards	ISO 668 (Classification & Dimensions) / ISO 1496 (Testing) / CSC Convention
20ft Standard (1 TEU)	External: 20'0" × 8'0" × 8'6" (6.06 × 2.44 × 2.59 m) \| Internal: 19'4" × 7'8" × 7'10" (5.90 × 2.35 × 2.39 m)
20ft Tare & Payload	Tare Weight: ~2,300 kg (5,070 lbs) \| Max Payload: 28,180 kg (62,130 lbs) \| Volume: 33.2 m³ (1,172 cu ft)
40ft Standard (2 TEU)	External: 40'0" × 8'0" × 8'6" (12.19 × 2.44 × 2.59 m) \| Internal: 39'5" × 7'8" × 7'10" (12.03 × 2.35 × 2.39 m)
40ft Tare & Payload	Tare Weight: ~3,750 kg (8,268 lbs) \| Max Payload: 26,730 kg (58,930 lbs) \| Volume: 67.7 m³ (2,390 cu ft)
40ft High Cube (HQ)	External Height: 9'6" (2.89 m) \| Internal Height: 8'10" (2.69 m) \| Volume: 76.4 m³ (2,700 cu ft)
Door Opening Dimensions	Width: 7'8" (2.34 m) \| Standard Height: 7'6" (2.28 m) \| High Cube Height: 8'6" (2.58 m)
Pallet Capacity	20ft: 11 Euro pallets / 10 GMA pallets \| 40ft: 25 Euro pallets / 20–21 GMA pallets

Standard ISO Shipping Container Technical Specifications Matrix

Container Type	External L × W × H (ft)	Internal L × W × H (m)	Tare Weight	Max Gross Mass (MGM)	Cubic Volume
20ft Standard (20' GP)	20'0" × 8'0" × 8'6"	5.90 × 2.35 × 2.39 m	2,300 kg (5,070 lbs)	30,480 kg (67,200 lbs)	33.2 m³ (1,172 ft³)
40ft Standard (40' GP)	40'0" × 8'0" × 8'6"	12.03 × 2.35 × 2.39 m	3,750 kg (8,268 lbs)	30,480 kg (67,200 lbs)	67.7 m³ (2,390 ft³)
40ft High Cube (40' HC)	40'0" × 8'0" × 9'6"	12.03 × 2.35 × 2.69 m	3,900 kg (8,598 lbs)	30,480 kg (67,200 lbs)	76.4 m³ (2,700 ft³)
45ft High Cube (45' HC)	45'0" × 8'0" × 9'6"	13.56 × 2.35 × 2.69 m	4,800 kg (10,580 lbs)	30,480 kg (67,200 lbs)	86.0 m³ (3,040 ft³)

TEU Definition and Intermodal Twistlock Geometry

The TEU Benchmark: The Twenty-Foot Equivalent Unit (TEU) is the universal unit of cargo capacity in container shipping. One 20ft container equals 1 TEU; one 40ft container equals 2 TEU.
ISO Corner Castings & Twistlocks: All containers feature 8 structural cast-steel corner blocks standardized under ISO 1161. Heavy harbor gantry spreaders and ship deck twistlocks engage with an oval aperture and rotate 90° to lock containers vertically against 30° roll accelerations at sea.