Is the finished width of 12 foot Corrugated Galvanized Steel 29-Gauge Roof Panel 24 inches wide? Is there extra width for overlap?

The panels are 25-5/8" overall width.

Gibraltar Corrugated Roofing Panels are 25-5/8" overall width. Manufacturer recommended installation states overlap 1 corrugation for siding application, leaving 24" coverage and overlap 2 corrugations for roofing application, leaving 21-1/2" coverage.