Case Size & Lug GuideWatchmaking & Horology

Analyze watch case diameter proportions, lug-to-lug spans, and find the corresponding standard strap lug-width sizes.

Parameters & Inputs
Watch Case Diameter (Bezel mm)40 mm
Wrist Circumference (Wrist Span mm)170 mm
140 mm (Slim Wrist)175 mm (Average)220 mm (Broad Wrist)

Calculations derived from Swiss and Japanese chronometric engineering standards. Always refer to your watch movement user manual to avoid shearing delicate calendar teeth or stripping winding stems.

Computed Technical Performance
Optimal Strap Lug Width20 mm
Lug-to-Lug Height Span48 mm
Proportion SuitabilityProportionate Classic Fit

Perfect classic mechanical sizing. Balanced case footprint for supreme wear comfort.

Mechanical Timekeeping ModulatorsEscapements / Jewels / ATM Seals

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