Free tool
Watch size calculator: what fits your wrist
Enter the measurement around your wrist. You get the width of its flat top, the case sizes that sit in proportion on it, and a verdict for any watch you are thinking about.
Measured just below the wrist bone, where a watch sits.
Case diameter without the crown, 30 to 50 mm. Or pick a size in the chart.
- Flat top of your wrist
- 52.5 mm
2.07 in across
- Cases that sit proportional
- 38 to 41 mm
Lug-to-lug about 46 to 49 mm
Enter a case diameter, or pick a size in the chart, to check a watch.
Each bar is a case's estimated lug-to-lug, drawn to scale against the flat top of your wrist. Tap one to check it.
Why lug-to-lug matters more than diameter
Case diameter is the number on the spec sheet, but it is not what decides the fit. Lug-to-lug is: the distance from the tip of the top lugs to the tip of the bottom ones, along the strap. That span has to rest on the flat top of your wrist. When the lugs reach past its edges, the watch sits on its lugs instead of the wrist and hangs over the sides, however modest its diameter reads.
The flat top is roughly the wrist's circumference divided by pi. The calculator compares the lug-to-lug with it: under 0.85 of the width wears small, 0.85 to 0.95 sits proportional, 0.95 to 1.05 wears large, and past that it overhangs.
Why 1.2 times is an estimate
Few spec sheets list lug-to-lug, so the calculator estimates it as 1.2 times the case diameter. That is close for most round watches with ordinary lugs. It misleads with:
- Cushion and tonneau cases. The case carries its width out toward the lugs, so it wears larger than a round case of the same diameter.
- Long or straight lugs. Many dive watches and some vintage designs run well past 1.2 times. Look up the real figure.
- Integrated bracelets. The first links are part of the case and do not bend, so the rigid span is longer than the lugs alone.
- Very thick cases. A tall case sits higher on the wrist and wears bigger than its width, even when the lugs fit.
When you know the real lug-to-lug, divide it by your flat top and read it against the same bands.
Wrist size chart
| Wrist | Flat top | Sits proportional |
|---|---|---|
| 140 mm5.5 in | 44.6 mm1.75 in | 32 to 35 mm |
| 150 mm5.9 in | 47.7 mm1.88 in | 34 to 37 mm |
| 160 mm6.3 in | 50.9 mm2.01 in | 37 to 40 mm |
| 170 mm6.7 in | 54.1 mm2.13 in | 39 to 42 mm |
| 180 mm7.1 in | 57.3 mm2.26 in | 41 to 45 mm |
| 190 mm7.5 in | 60.5 mm2.38 in | 43 to 47 mm |
| 200 mm7.9 in | 63.7 mm2.51 in | 46 to 50 mm |
How to measure your wrist at home
- Wrap a strip of paper or a soft tape around your wrist just below the wrist bone, where a watch sits.
- Keep it snug but not tight, the way you would wear a strap.
- Mark where the end meets the strip. Lay the paper flat on a ruler and read the length.
- Enter it above in millimetres or inches. Measure twice to be sure of the number.
Questions
What size watch should I wear for a 6.5 inch wrist?
A 6.5 inch wrist is about 165 mm around, so its flat top is about 52.6 mm wide. Round cases from 38 to 41 mm sit proportional on it, with an estimated lug-to-lug of 46 to 49 mm. Smaller cases wear small; from 42 mm up they start to wear large.
What size watch fits a 7 inch wrist?
A 7 inch wrist is about 178 mm around, so its flat top is about 56.6 mm wide. Round cases from 41 to 44 mm sit proportional on it, with an estimated lug-to-lug of 49 to 53 mm. Smaller cases wear small; from 45 mm up they start to wear large.
Why does lug-to-lug matter more than case diameter?
Lug-to-lug is the span from the tip of the top lugs to the tip of the bottom ones, and it is the part of the watch that has to sit on the flat top of your wrist. Case diameter leaves the lugs out. Two 40 mm watches can wear very differently: short, curved lugs keep one inside the wrist, long straight lugs make the other overhang.
How do I measure my wrist for a watch?
Wrap a strip of paper or a soft tape around your wrist just below the wrist bone, where a watch sits. Keep it snug but not tight, mark where it meets, and read the length off a ruler in millimetres or inches.
Is 1.2 times the case diameter always the right lug-to-lug?
No. It is an estimate for round cases with ordinary lugs. Cushion cases, long or straight lugs, integrated bracelets and very thick cases all wear larger than it suggests. When you know the real lug-to-lug, divide it by your wrist's flat top: 0.85 to 0.95 sits proportional, below that wears small, and from 1.05 up it overhangs.
The WORN app
Your wrist, measured once, read against every watch.
WORN measures your wrist with the iPhone's depth camera. On iPhones without one, you set it by hand. Every watch in the app is then read against that number, so you can see how a watch sits on your wrist before you buy it.