How to read a size/type code
The four characters split into three fields:
- Character 1 — length. 2 is 20 ft, 4 is 40 ft and L is 45 ft. Length code 5 is unassigned, so a 45 ft unit uses L rather than 5.
- Character 2 — height and width. It encodes the container's height together with whether it is standard or extra width; for example a value here distinguishes a standard 8 ft 6 in box from a 9 ft 6 in high cube.
- Characters 3 and 4 — type. A letter and a digit naming the kind of container and a variant, such as G for a general-purpose box or R for a refrigerated (reefer) one.
Common size/type codes
| Code | Means |
|---|---|
| 22G1 | 20 ft standard-height general-purpose container |
| 42G1 | 40 ft standard-height general-purpose container |
| 45G1 | 40 ft high-cube general-purpose container |
| 45R1 | 40 ft high-cube refrigerated (reefer) container |
| 22R1 | 20 ft refrigerated container |
Type groups you will meet include G (general purpose), R and H (thermal/reefer), U (open top), T (tank), P (platform and flat rack) and S (named cargo). The exact type digit depends on the variant.
Decode a specific code
The reference library has an interactive size/type decoder that resolves a code to its length, height, width, type and TEU, and marks anything unknown as undefined rather than guessing.
Why the size/type code has no check digit
The size/type code is descriptive metadata, not an identifier, so it is never a check-digit target and is never altered when Checkdigit corrects a file. Only the container number carries a check digit.