Getting your wrist measurement right takes under a minute and is the foundation of every watch-size decision. Here are three accurate ways to do it — with or without a tape measure.
Wrap a soft tailor's tape measure around your wrist just below the wrist bone, where you'd normally wear a watch. Keep it snug but not tight — you should be able to slip a finger under it.
Note where the tape meets, reading in centimetres or inches. This number is your wrist circumference — the single most important measurement for watch sizing.
Wrap a strip of paper or a piece of string around your wrist, mark where it overlaps, then lay it flat against a ruler to read the length.
For the most accurate lug-to-lug guidance, measure the flat width across the top of your wrist with a ruler or caliper. This caps how long a watch can be before the lugs overhang.
Plug your circumference and style into the Watch Size Calculator to get a recommended case diameter, maximum lug-to-lug and strap width.
Wrist circumference scales directly with the case diameter you can carry. As a quick guide: a 6-inch (15 cm) wrist suits 34–40 mm, a 7-inch (18 cm) wrist suits 38–42 mm, and an 8-inch (20 cm) wrist suits 42–46 mm. Measure accurately and the rest of watch sizing falls into place.
Wrap a flexible tape measure (or a strip of paper) around your wrist just below the wrist bone, snug but not tight. Read the circumference in cm or inches. That measurement tells you which case diameter range will fit — for example, a 17 cm (6.7 inch) wrist suits roughly 38–42 mm.
Measure just below the wrist bone (the ulnar styloid), which is where a watch naturally sits. Measuring higher up the forearm gives a larger, misleading number.
The average adult wrist is around 6.5–7.5 inches (16.5–19 cm). Wrists under 6.5 inches are small and suit 34–40 mm watches, while wrists over 7.5 inches are large and comfortably wear 42 mm and up.
Snug but comfortable — you should be able to fit one finger between the tape and your skin. That mirrors how a watch strap should sit, so the recommendation reflects real-world fit.
Circumference alone is enough for a good case-diameter recommendation. Measuring the flat wrist width is optional but makes the lug-to-lug guidance more precise, which matters most on smaller wrists.
Get an instant case, lug-to-lug and strap recommendation.
Best case sizes for a smaller 6" (15 cm) wrist.
The medium 6.5" (16.5 cm) wrist sweet spot.
The versatile 7" (18 cm) wrist explained.
Sizing a larger 7.5" (19 cm) wrist.
Big-watch options for an 8" (20 cm) wrist.
How 2 mm changes the look and fit.