Tool

Wrist size to watch size

Enter your wrist circumference to get a case diameter range and a maximum lug-to-lug length. These are common rules of thumb, not a guarantee: how a watch wears also depends on its thickness, lug shape and strap.

Unit

Wrap a strip of paper or a soft tape just above the wrist bone, where the watch sits.

Wrist shape (optional)

Rule-of-thumb result

Case diameter
––– mm
Lug-to-lug, at most
– mm

A guide, not a guarantee. Many people happily wear sizes outside these ranges.

How the numbers are worked out

  1. Convert the wrist to millimetres (cm × 10, or inches × 25.4). We accept 12 to 25 cm.
  2. Centre size = 0.235 × wrist in mm. The diameter range is that centre ± 2 mm.
  3. Maximum lug-to-lug = 0.29 × wrist in mm, a stand-in for keeping the lugs within the flat top of the wrist.
  4. A flatter wrist adds 1 mm to the centre and 2 mm to lug-to-lug; a rounder wrist takes the same away.
  5. Every result is rounded to the nearest 0.5 mm.

The factors reproduce the size bands commonly quoted by retailers and enthusiasts. They are not derived from measurements of any watch in the catalogue.

Typical results

WristDiameterLug-to-lug max
15 cm (5.9 in) 33.5–37.5 mm 43.5 mm
16 cm (6.3 in) 35.5–39.5 mm 46.5 mm
17 cm (6.7 in) 38–42 mm 49.5 mm
18 cm (7.1 in) 40.5–44.5 mm 52 mm
19 cm (7.5 in) 42.5–46.5 mm 55 mm
20 cm (7.9 in) 45–49 mm 58 mm

See also: small watches (38 mm and under) · large watches (43 mm and over)