Enter your watch's lug width and get the exact strap width, spring bar length, recommended bar diameter and matching taper options. Built on industry-standard horological conventions.
Drag to your wrist circumference. A correctly sized strap buckles on the middle hole.
Diameter of the bar tube, chosen by strap type, not width.
| 1.8 mm | Standard. Fits the majority of leather, NATO and steel-end straps. |
| 1.5 mm | Dressier and thinner straps, smaller cases, slim lugs. |
| 1.2 mm | Very thin or soft straps and widths under ~15 mm. |
Taper is written lug width / buckle width. A 20/16 strap is 20 mm at the case and narrows to 16 mm at the buckle, so it needs a 16 mm buckle. Common pairings below.
| Lug width | Common tapers (lug / buckle) | Spring bar length | Typical diameter |
|---|---|---|---|
| 18 mm | 18/16 · 18/18 | 18 mm | 1.5-1.8 mm |
| 19 mm · | 19/16 · 19/18 | 19 mm | 1.5-1.8 mm |
| 20 mm | 20/16 · 20/18 · 20/20 | 20 mm | 1.8 mm |
| 21 mm · | 21/18 · 21/20 | 21 mm | 1.8 mm |
| 22 mm | 22/18 · 22/20 · 22/22 | 22 mm | 1.8 mm |
| 24 mm | 24/20 · 24/22 · 24/24 | 24 mm | 1.8 mm |
| 26 mm | 26/22 · 26/24 · 26/26 | 26 mm | 1.8 mm |
Lug width is the inner distance between the two lugs where the strap sits, not the case diameter.
With a caliper or millimetre ruler, measure the inside gap with the strap removed. Round to the nearest whole millimetre.
Many straps are stamped with their size on the underside. If present, it confirms your measurement.