The foot unit of measure was used widely across the Roman Empire. It was estimate to be about 295 mm (11.6") or so. The influence of the Roman standards spread across new territories as they were conquered.

Some common units used were: 1 digit or "digitus" = 18.44 mm 1 inch or "unica" = 24.58 mm 4 digits or 3 inches = 1 small palm or "minor palmus" 12 digits or 9 inches = 1 large palm or "major palmus" 16 digits or 12 inches = 1 foot or "pes" 24 digits or 18 inches = 1 cubit or "cubitus 5 feet = 1 pace or "passus" 10 feet or 2 paces = 1 "decempeda" 120 feet or 24 paces = 1 actus" 625 feet or 24 paces = 1 "actus" 1000 paces or 8 stadia = 1 "milliarium" or "mille passus (this is where we get the term mile!!)