Strap Sizing Calculator
Recommends strap length and spring-bar width based on wrist size and lug width.
13 cm21 cm
16 mm24 mm
Recommendation
112/78 mm (long/short)
Most collector straps: 75/115 (small), 80/120 (M), 85/125 (L), 90/130 (XL).
Spring bar20 mm spring bars (1.8 mm diameter standard)
Leather straps shrink ~3% over the first month. Choose one hole longer than perfect-fit on day one.