Paris ligne, duodecimal length unit of watchmakers

This traditional and in watchmaking still prevailing duodecimal length unit is derived from the former general basic unit “Paris foot”. A “Paris foot” corresponds to 3247 mm.

• 1 Paris foot (´) = 12 Paris inches (´´)
• 12 Paris inches (´´) = 144 lignes (´´´)
• 1 ligne (´´´) = 2.2558 mm or 0.08881 inches

• Conversion table: Lignes <-> Millimeters