Guides. Forget case diameter. One number decides whether a watch hugs your wrist or hangs off it, and this calculator tells you yours in under a minute.
Will it fit your wrist?
Enter your wrist size, then the watch’s lug-to-lug from its spec sheet. No lug-to-lug listed? Use the case diameter instead.
Start with your wrist size
Wrap a strip of paper around your wrist where you wear a watch, then measure it against a ruler.
Sweet spotStill fitsMaximumThis watch
Two watches can both be 40 mm and wear completely differently. One sits neatly on a slim wrist; the other hangs off the sides like a borrowed jacket. The reason is not the diameter on the box. It is lug-to-lug.
Why lug-to-lug matters more than diameter
Lug-to-lug is the distance from the tip of the top lugs to the tip of the bottom lugs, measured straight across the watch. It is the true length of the watch head on your wrist. Diameter tells you how wide the dial looks; lug-to-lug tells you whether the watch actually fits. The top of every wrist is roughly flat, and a watch only looks right when its lugs stay on that flat part.
Measure your wrist in 30 seconds
- Wrap a strip of paper, a thread or a phone charger cable around your wrist, just above the wrist bone, where you would wear a watch.
- Keep it snug but not tight, and mark where the end overlaps.
- Lay it flat against a ruler. That length is your wrist size. Round it to the nearest centimetre and find your row below.
The HORAKAA fit chart
| Wrist size | Sweet spot (lug-to-lug) | Maximum | Case diameter |
|---|---|---|---|
| 14 cm (5.5 in) | 37–40 mm | 42 mm | 32–36 mm |
| 15 cm (5.9 in) | 40–43 mm | 45 mm | 34–38 mm |
| 16 cm (6.3 in) | 42–46 mm | 48 mm | 36–39 mm |
| 17 cm (6.7 in) | 45–48 mm | 51 mm | 38–41 mm |
| 18 cm (7.1 in) | 48–51 mm | 54 mm | 39–42 mm |
| 19 cm (7.5 in) | 50–54 mm | 57 mm | 40–44 mm |
| 20 cm (7.9 in) | 53–57 mm | 60 mm | 42–45 mm |
| 21 cm (8.3 in) | 56–60 mm | 63 mm | 43–47 mm |
The ruler test: the most accurate check
Two people with the same wrist size can have very different wrists. A round wrist has a narrow flat top; a flat, wide wrist has more room. So for a watch you really want, try this. Hold a ruler across the top of your wrist and measure the flat part only, from where it starts to curve down on one side to where it curves down on the other. A watch fits well when its lug-to-lug is no longer than that number.
How popular watches measure up
| Watch | Case diameter | Lug-to-lug (approx.) |
|---|---|---|
| Casio F-91W | 35 mm | 38 mm |
| Vostok 581096 Prestige | 38 mm | 45 mm |
| Seiko SKX007 | 42 mm | 46 mm |
| Omega Speedmaster Professional | 42 mm | 48 mm |
Notice the Seiko. At 42 mm it sounds big, but its short lugs keep it at about 46 mm lug-to-lug, so it wears comfortably on a 16 or 17 cm wrist. That is exactly why diameter alone can mislead you.
Three things that change the fit
Curved lugs. Lugs that bend down towards the wrist hug it, so a watch with curved lugs can go a couple of millimetres past your maximum and still look fine. Straight, flat lugs are less forgiving.
Thickness. A thick watch sits higher and looks bigger than its numbers. On a slim wrist, anything over about 13 mm thick will feel chunky even if the lug-to-lug fits.
Strap or bracelet. A soft leather or fabric strap bends right at the lugs and wears smaller. A bracelet with a stiff first link, or an integrated design, effectively makes the watch longer. Add a few millimetres to the lug-to-lug in your head for those.
What is your wrist size, and which watch surprised you by fitting better or worse than you expected? Tell us on Instagram at @horakaaofficial.
Sources: fit ranges are a Horakaa guide based on common watch-sizing advice and are approximate. Watch dimensions are approximate figures from brand and reseller listings; check the maker’s specifications before buying. Image: Horakaa (AI-generated illustration).