# ISO 6346 4-Character Container Size and Type Code Directory
> Decode ISO 6346 4-character size and type codes into precise metric and imperial dimensions and cargo types.

- **Canonical URL:** https://stanzaapi.com/tools/container-validator/iso-6346/container-size-type-codes
- **Governing Standard:** ISO 6346 / BIC Container Prefix Coding (Bureau International des Conteneurs (BIC) & ISO)
- **Latency:** <1ms Edge
- **Privacy:** In-memory execution only (zero data stored or logged)

## Technical Overview & Governing Rules
The 4-character size/type code indicates container length (1st char), height/width (2nd char), and container type with special features (3rd and 4th chars).

## Specification Matrix
| Code | Length | Height | Type |
| --- | --- | --- | --- |
| 22G1 | 20 ft (6.058 m) | 8 ft 6 in (2.591 m) | General Purpose Container |
| 42G1 | 40 ft (12.192 m) | 8 ft 6 in (2.591 m) | General Purpose Container |
| 45G1 | 40 ft (12.192 m) | 9 ft 6 in (2.896 m High Cube) | General Purpose Container with ventilation |
| 45R1 | 40 ft (12.192 m) | 9 ft 6 in (High Cube) | Refrigerated Thermal Container (Reefer) |
| 22U1 | 20 ft (6.058 m) | 8 ft 6 in | Open Top Container |
| 22T1 | 20 ft (6.058 m) | 8 ft 6 in | Tank Container for liquids |

## Standard JSON Response Model
```json
{
  "code": "45G1",
  "lengthFeet": 40,
  "heightFeet": 9.5,
  "type": "General Purpose High Cube"
}
```

## Frequently Asked Questions & Edge Cases
### Q: What does the 4th digit in 45G1 indicate?
**A:** The 4th character describes specific features like passive ventilation openings.