The Forty-Foot Container is the 40-foot ISO general-purpose intermodal container, twice the length of a 20-foot container but with the same width and standard height. Coded “40’GP” or “40’DC” by carriers, the container has internal dimensions of approximately 12.0 m × 2.35 m × 2.39 m, payload capacity of 28-30 MT, and volume capacity of approximately 67 cubic metres. The 40-foot container counts as 2 TEU in shipping statistics, but the FEU (Forty-foot Equivalent Unit) measure is used in some carrier and route reporting. For chemical sourcing the 40’GP is the workhorse for cargoes at scale where the additional volume over 20’GP can be fully utilised.
Standard 40’GP dimensions and capacity
| Dimension | External | Internal |
|---|---|---|
| Length | 12.192 m (40 feet) | 12.032 m |
| Width | 2.438 m (8 feet) | 2.352 m |
| Height | 2.591 m (8 feet 6 inches) | 2.393 m |
| Door height | n/a | 2.275 m |
| Door width | n/a | 2.343 m |
| Maximum gross mass | 32,500 kg (international standard) | n/a |
| Tare mass | ~3,800-4,000 kg | n/a |
| Maximum payload | ~28,500-28,700 kg | n/a |
| Internal volume | n/a | ~67.7 m³ |
The maximum payload is similar to 20’GP, the additional length adds volume but not weight capacity. This is the structural reason 40’GP is preferred for low-density and volume-out cargo, while 20’GP works for high-density and weight-out cargo.
Cargo capacity for chemical formats
| Cargo format | Capacity per 40’GP |
|---|---|
| 200-kg drums on pallets (4 drums per pallet, 20 pallets) | 80-160 drums depending on pallet stacking; typically 80 single-tier (~16 MT) or 160 double-stacked (~32 MT, exceeds weight limit) |
| 220-kg drums on pallets (4 drums per pallet) | 80 drums single-tier (~17.6 MT cargo) |
| 1,000-kg IBCs | 32-40 IBCs (cargo weight at IBC limits 28-30 MT, often weight-out before volume) |
| 1,000-kg big bags | 36-40 bags (~36-40 MT, exceeding weight limit if at 1 MT each, typically loaded at 800-900 kg per bag for 30 MT cargo total) |
| 25-kg paper bags on pallets (40 bags per pallet, 26-28 pallets) | 1,040-1,120 bags (~26-28 MT cargo) |
The 40’GP advantage over 20’GP is most pronounced for cargoes that cube out before they weight out, low-density bulk solids, fluffy granulars, packaged consumer goods. For dense liquid drums, 40’GP capacity is often duplicated by simply running two 20’GP containers at lower per-shipment risk.
When 40’GP is the right container
40’GP is the right choice for:
- Volume cargo above ~16 MT that fits 40’GP volume, chemical buyers running 20-25 MT shipments of drum cargo
- Low-to-medium density cargo that cubes out the 67 m³ before reaching the 28-30 MT weight limit
- Routes with significantly lower 40’GP rates per cubic metre than 20’GP, typical for trans-Pacific and trans-Atlantic lanes where 40-foot capacity is the dominant carrier offering
When 40’GP is the wrong container
40’GP is wrong for:
- Cargo at exactly 16 MT that fits 20’GP perfectly and pays a 30%+ rate premium for the larger box that ships 50% empty
- Low-volume specialty chemical orders where the additional volume is wasted
- Routes where 40-foot service is limited, some smaller ports and inland destinations have 20-foot-only handling
40’GP vs 40’HC
The standard 40’GP has 2.591 m external height. The 40’HC (40-foot High Cube) is 2.896 m external height, about 30 cm taller. The HC variant adds approximately 11 cubic metres of volume capacity at marginally higher tare mass.
For chemical cargo specifically:
- Drum cargo: 40’GP and 40’HC both fit 80 drums single-tier; HC gains nothing
- IBC cargo: 40’GP fits 32-40 IBCs depending on pallet style; HC marginally helps with double-stacking
- Big bag cargo: 40’HC fits 1-2 more bags per container with double-stacked configurations
- Bulk pallet cargo with double-stacking: 40’HC adds ~15-20% volume utilisation
For volume buyers running double-stack-friendly cargo, 40’HC is preferred. For drum-heavy chemical cargo, 40’GP and 40’HC are equivalent at the loading mass.
Hazmat surcharges on 40’GP
40’GP hazmat surcharges typically run 1.5-2× the 20’GP rates for the same cargo class, reflecting the additional cargo at risk:
| IMDG class | Hazmat surcharge per 40’GP |
|---|---|
| Class 3 | USD 150-500 |
| Class 8 | USD 150-500 |
| Class 5.1 | USD 300-800 |
| Class 6.1 | USD 500-1,200 |
Operator note: the SOLAS VGM and 40’GP
The verified gross mass requirement applies to 40’GP equivalently to 20’GP. For 40’GP cargo, declared VGM = cargo + packaging + tare ~ 30 MT typical. Misdeclarations are routinely caught by the carrier weighbridge or the destination port. Industry practice is to keep loaded weight 1-2 MT below the declared VGM to allow for measurement variance.
Related terms
Twenty-foot container is the smaller standard size. Forty-foot High Cube adds 30 cm of height for additional volume. Reefer container is the temperature-controlled variant. IBC, drum, and big bag are standard cargo formats inside 40’GP.