Gauges and Measuring

Why measure your crystal?

A watch crystal is chosen first by its diameter, then by its thickness and shape (flat, domed, with or without a magnifier). A difference of a few tenths of a millimetre is enough for a crystal to be loose or not fit: an accurate measurement avoids ordering mistakes.

• Diameter: measured between the outside jaws, taking several readings while turning the crystal.
• Thickness: measured at the edge, then at the centre for a domed crystal.
• Seat: if the crystal is lost, measure the inside diameter of the bezel or case.

A digital caliper shows the value directly and makes tenths and hundredths of a millimetre easy to read.

Follow our guide measuring with a caliper, then use the find my crystal tool. To choose the material, read types of watch crystal.