The global shipping industry runs on standardized steel boxes — but those boxes come in far more varieties than most shippers realize. Choosing the wrong container type can mean cargo that does not fit, freight that arrives damaged because temperature control was not specified, or paying for a full container when you needed an open-top for over-height cargo. This guide covers every standard container type in active use, with exact dimensions, typical use cases, and cost considerations.
20ft General Purpose (20ft GP): The Workhorse of Global Trade
The 20ft General Purpose container, also called a 20ft Dry Van, is the standard unit of global trade — so standard that the term TEU (Twenty-foot Equivalent Unit) is the universal measure of container shipping capacity. Exterior dimensions: 20ft (6.058m) long × 8ft (2.438m) wide × 8ft 6in (2.591m) high. Interior dimensions: approximately 5.898m × 2.350m × 2.393m. Maximum payload: approximately 21,700 kg. Usable capacity: approximately 33 CBM. Best for: dense, heavy cargo that would fill the weight limit before filling the volume — such as heavy machinery, metallic goods, canned goods, chemicals, and construction materials. Not ideal for lightweight, bulky goods where you would hit the volume limit before the weight limit. A 20ft container is the most widely available container type at ports worldwide and generally the easiest to place on short notice.
40ft General Purpose (40ft GP): Twice the Volume, Not Double the Cost
The 40ft GP container is exactly twice the length of a 20ft container and is the most common choice for most commercial shippers. Exterior dimensions: 40ft (12.192m) long × 8ft (2.438m) wide × 8ft 6in (2.591m) high. Interior dimensions: approximately 12.030m × 2.350m × 2.393m. Maximum payload: approximately 26,500 kg. Usable capacity: approximately 67 CBM. While the volume is double a 20ft container, the ocean freight rate for a 40ft container is typically only 1.4–1.7× the rate for a 20ft container on the same route — making a 40ft container significantly more economical on a per-CBM basis for most cargo. The 40ft GP is the standard choice for most consumer goods: clothing, electronics, household goods, automotive parts, and any cargo where volume rather than weight is the limiting factor.
40ft High Cube (40ft HC): Extra Headroom for Bulky Cargo
The 40ft High Cube container is identical to the standard 40ft GP except for one key difference: it is 9ft 6in (2.896m) tall instead of the standard 8ft 6in. This provides an extra 30cm of internal height, increasing the usable capacity from approximately 67 CBM to approximately 76 CBM. The 40ft HC has become the de facto standard for most full container load (FCL) shipments over the past decade — many carriers now offer primarily High Cube containers on major trade lanes. Best for: furniture, mattresses, large appliances, clothing on hangers (using garment rails), automotive parts, and any lightweight but bulky cargo that benefits from the additional height. The 40ft HC is increasingly available at standard 40ft pricing on most routes, though some carriers and ports charge a small premium.
Reefer Containers: Controlled Temperature for Perishables
Reefer containers (refrigerated containers) are standard container units with built-in refrigeration equipment that maintains a set temperature throughout the voyage. Available in 20ft and 40ft lengths. Temperature range: most modern reefer containers maintain temperatures from -30°C to +30°C, making them suitable for frozen meat (-18°C), fresh fruit (+2°C to +8°C), pharmaceuticals (+2°C to +8°C or +15°C to +25°C), and even some chemicals requiring temperature control. Key specifications: the refrigeration unit is powered by the ship's electrical supply at sea (reefer plugs on the vessel) and by a generator or shore power at the port. The shipper must specify the required set-point temperature, ventilation settings, and humidity (for fresh produce) in the shipping instructions. Reefer freight rates are typically 2.5–4× the standard dry container rate for the same route, reflecting the cost of the refrigeration unit, energy consumption, and more intensive monitoring. Reefer containers require reefer plugs at both the origin and destination ports — verify availability before booking.
Open Top Containers: For Over-Height Cargo
Open Top containers have no rigid roof — instead, they use removable or rolling bows (arches) and a tarpaulin cover. This allows loading from the top using a crane, which is essential for cargo that exceeds the internal height of a standard container. Standard dimensions match the 20ft or 40ft GP, but the open roof allows cargo to exceed the standard 2.39m internal height limit — subject to vessel and port height restrictions, over-height cargo can often be 2.5–3.5m above the container floor. Common cargo: machinery with tall profiles, steel coils, marble slabs, construction equipment, and any cargo where the only practical loading method is crane from above. Open Top containers attract a premium of typically $200–$600 over standard dry rates, plus additional charges for tarpaulin, crane lifts, and over-height surcharges from the carrier.
Flat Rack Containers: For Over-Width or Over-Length Cargo
Flat Rack containers are platforms with end walls but no side walls or roof. They allow cargo that is over-width, over-length, or irregular in shape to be secured to the platform and loaded onto the vessel. Collapsible Flat Racks (also called flatrack or FR) can have their end walls folded down for more compact stowage when empty. Common dimensions: 20ft FR (approximately 5.94m × 2.35m platform) and 40ft FR (approximately 12.13m × 2.12m platform). Typical over-dimension allowances: cargo can overhang the sides by up to 30cm per side and can exceed the standard height. Common cargo: yachts, boats, large vehicles, construction machinery (excavators, cranes), industrial boilers, and any cargo that cannot fit inside a standard container due to its shape. Flat Rack shipments require specialized securing (lashing and blocking by certified riggers), detailed stowage plans, and prior approval from the carrier. Rates are typically 2–4× standard container rates plus lashing charges.
Tank Containers: For Liquids and Gases
Tank containers are cylindrical pressure vessels mounted within a standard ISO frame. They are designed for transporting liquids, gases, and powders in bulk. Standard capacity: 17,500–26,000 liters. Minimum fill requirement: typically 80% to prevent cargo from sloshing and creating instability. Tank containers are used for: food-grade liquids (edible oils, juice concentrates, wine, alcohol), chemicals (solvents, adhesives, resins), hazardous liquids (acids, caustics, flammable liquids), and gases (propane, chlorine, ammonia in pressurized tanks). Tank containers must comply with UN portable tank instructions (T-codes) based on the hazard classification of the cargo. The shipper is responsible for cleaning the tank before and after use, which is handled by tank-cleaning depots and is typically the shipper's cost. Cleaning costs of $300–$800 per tank are common and must be factored into the total freight cost.
LCL: Sharing a Container with Other Shippers
Less than Container Load (LCL) is not a separate container type — it is a shipping mode where your cargo occupies a portion of a container shared with other shippers' goods. An LCL consolidation operator (consolidator or groupage agent) collects cargo from multiple shippers, packs it into a container at a Container Freight Station (CFS), and ships the consolidated container to the destination port, where it is deconsolidated at another CFS. LCL is economical for shipments of 1–10 CBM. Above 10–12 CBM, FCL in a 20ft container usually becomes more cost-effective. The additional handling at origin and destination CFS adds time (typically 3–5 days) and risk (more handling = more opportunity for damage). LCL shipments are quoted and tracked differently from FCL: you receive an LCL House Bill of Lading rather than a master Bill of Lading directly from the ocean carrier.
How to Choose the Right Container for Your Cargo
Use this decision framework: (1) Calculate your cargo's CBM and weight. If CBM > 12 or weight > 15,000 kg, consider FCL. (2) Check if your cargo requires special handling: temperature-sensitive → Reefer; over-height → Open Top; over-width/length or irregular shape → Flat Rack; liquid bulk → Tank. (3) For standard dry cargo on FCL: if CBM is 28–45 CBM, use a 20ft container. If CBM is 45–70 CBM, use a 40ft GP or HC. The 40ft HC is usually the better choice for most cargo due to the extra volume at minimal additional cost. (4) For LCL: appropriate for 1–12 CBM of standard cargo without special requirements. (5) Always confirm container availability at your origin port before booking — equipment imbalances can cause delays and substitutions.
Container Tracking by Type
Container numbers follow the same ISO 6346 format regardless of type, but the equipment category identifier (the 4th letter in the container number) distinguishes them: "U" is standard freight containers (GP, HC, Reefer, Open Top), "J" is detachable freight container equipment, "Z" is trailer and chassis. When tracking on Trackora, paste your full container number — confirm the shipping line on your booking or B/L and select that carrier; the equipment prefix alone does not establish the carrier for this journey. For Reefer containers, some carriers provide additional monitoring data including temperature logs accessible through their proprietary portals.