How do I measure my arm circumference?

To measure your arm circumference, all you need is a thicker thread and a ruler.

  1. Wrap your wrist with the thread so that it fits comfortably with you.
  2. Now mark the crossing ends of the thread with a pencil.
  3. Then place the thread with the mark on a ruler. Measure from point to point.

Please note: There should still be a finger-width distance between the wrist and the bracelet, as the wrist swells a little during the day.

This result is your bracelet size. Alternatively, you can use a tape measure.


Service and exchange, the products can be exchanged gladly. The return shipping costs are borne by the buyer.

You can choose a different size, model or product (as long as online terms and conditions and price differences, if any, are respected).

The clasp adds about 1-1.5 cm, for example, a bracelet ordered 18 cm large, is delivered about 19-.19.5 cm (including clasp), but it fits, or speaks the originally ordered size so 18.

Depending on the material or braid type or closure, the total length of the bracelet will be larger than ordered but the circumference will fit perfectly. The ordered size corresponds to the wrist circumference and not the total length of the bracelet, therefore a bracelet is rather ordered only after a correct measurement of the wrist !

The stronger the diameter of the bracelet, the more we need to add extra length. The reason is the compression of the material when it is bent, it becomes tighter inside. That's why it's important to measure the circumference of your wrist with a thin thread or a tape measure (which is also thin), otherwise the value of the order will not be correct.
If you like, try it: measure the length of the bracelet when it is straight. Then you close it. Now measure the inner circumference of your bracelet and you will find it is much less than in straight state.
Please do not take the length of another bracelet, this will lead to the wrong value!

All Constantin Nautics bracelets are handmade, for this reason they can be 2-3 mm different in size.