A watch’s dimensions help you compare sizes, but comfort also depends on wrist shape, case design and strap adjustment. Use this guide as a starting point, not a fit guarantee.

1. Measure your wrist

Wrap a flexible measuring tape around your wrist where you normally wear a watch. Keep it snug without compressing the skin. Record the circumference in centimetres or millimetres. If you use a strip of paper, mark where the ends meet, then lay it flat against a ruler. For example, 17 cm equals 170 mm.

Wrap tape around wrist → mark the meeting point
Lay flat: 0 ────────────────── mark
         Read your wrist circumference

Wrist circumference is not the same as the width of the top of your wrist. Two wrists with the same circumference can carry the same watch differently.

2. Compare the three case measurements

TOP VIEW (simplified)
          strap
        ┌─┐  ┌─┐  ← upper lug tips
        │ ┌──┐ │       ↕
        │ │  │ │   lug-to-lug
        │ └──┘ │       ↕
        └─┘  └─┘  ← lower lug tips
          strap
        ←──────→
        case width

SIDE VIEW (simplified)
        ┌────────┐  ↑
        └────────┘  ↓ thickness
Diagrams are not to scale.

Case diameter or width: the measurement across the case, usually excluding the crown unless stated otherwise. Round watches are commonly described by diameter; rectangular and irregular cases may use width. Compare with a watch you already enjoy wearing rather than relying on a universal wrist-size chart.

Case thickness: the height from the underside of the case to the top of the watch. Check whether the manufacturer includes the crystal or other protrusions. A thicker watch may sit higher and feel different under a sleeve.

Lug-to-lug length: the distance from the tips of the lugs at one end of the case to the tips at the other, along the strap direction. It helps estimate how far the watch spans across your wrist. Curved lugs can sit differently from straight lugs, and rigid bracelet end links can extend the effective span. Lug-to-lug is not lug width, which is the gap between the lugs for the strap.

3. Read manufacturer dimensions carefully

Always check the labels and units for the exact model/reference number. Manufacturers may list length × width × thickness, but the order is not universal. A hypothetical listing explicitly labelled length 48 mm × width 42 mm × thickness 12 mm describes a 42 mm-wide case, not a 48 mm diameter. Do not assume that “length” means lug-to-lug unless the specification or drawing confirms it.

Check whether measurements include the crown, protective guards, crystal or strap attachments. If lug-to-lug is not provided, treat it as unknown rather than estimating it from case diameter. Compare measurements taken on the same basis.

4. Check the strap and try the fit

Look for the strap or bracelet’s stated wrist-size range and adjustment options. Case size alone does not tell you whether a strap will fasten comfortably. When trying a watch, check that it stays comfortably in place, the lugs do not press into your wrist, and the crown does not dig in as you move your hand. Personal preference matters; no single dimension guarantees a comfortable fit.

Need help comparing a model or asking about sizing? Visit our Watch Services page or find a store location. Share the full model/reference number and your wrist measurement so our team can help you check the available information.