# Record Length

Use the RECL specifier to specify the record length.

The units used for specifying record length depend on the form of the data:

- Formatted files (FORM= 'FORMATTED'): Specify the record length in bytes.

- Unformatted files (FORM= 'UNFORMATTED'): Specify the record length in 4-byte units, unless you specify the assume byterecl compiler option to request 1-byte units.

For all but variable-length sequential records on 64-bit addressable systems, the maximum record length is 2.147 billion bytes (2,147,483,647 minus the bytes for record overhead). For variable-length sequential records on 64-bit addressable systems, the theoretical maximum record length is about 17,000 gigabytes. When considering very large record sizes, also consider limiting factors such as system virtual memory.

### Note

The RECL specifier is ignored for stream access.

Parent topic: Fortran I/O