How to determine strap size you need for your watch.

1.  You will need to measure between the lugs as shown.  In above case it is 20mm.  So you will need to look for 20mm straps or bracelets.  Most of the time measurement unit is in metric millimeters so it may be handy to have a metric ruler.  Special ruler is used above but regular metric ruler or measuring tape will do!

2. In above case, you've guessed it!  22mm.  Seek for 22mm wide strap or bracelet.

3. Here is the table for strap width popular brand/models.  Some models come in different case sizes, so please measure your actual watch.  This is table is for reference only.

Some models come in variations and depeding on the year of production there may be spec. change.

Brand/Model Strap Width
Breitling B1 22mm
Breitling Airborn 20mm
Breitling Chronomat 22mm
Breitling Cosmonaut 22mm
Breitling Navitimer 22mm
Breitling Blackbird 20mm
Breitling Spatiographe 22mm
Omega Speedmaster 18mm
Omega Speedmaster Professional 18mm, 20mm
Omega Dynamic 18mm
Omega Dynamic Chronograph 20mm
Omega Seamaster 300 19mm
Rolex Submariner 20mm
Rolex Sea-Dweller 20mm
Rolex GMT 20mm
Rolex GMT Master I & II 20mm
Rolex Explorer 19mm, 20mm
Seiko British Royal Airforce Broadarrow 20mm
Seiko 5 20mm
Seiko Prospex Divers 22mm
Seiko Divers SKX779 20mm
Seiko Divers SKX007K 22mm
Seiko Divers SKX009K 22mm
Seiko Divers SKX011J 22mm
Seiko Marinemaster Professional SBDX001 20mm
Sinn 156B Chronograph 20mm
Sinn EZM1 20mm
Sinn 144M 20mm
Sinn 603 EZM-3 20mm
Sinn 503 EZM-3 20mm
Sinn 103 Tiger 20mm
Sinn 356 Flieger 20mm
Sinn 156 EZM-4 20mm
Sinn 203 Chronograph 20mm
Sinn 142 Chronograph 20mm
Sinn 103 Chronograph 20mm
Sinn 756 Chronograph 20mm
Sinn 8828 Ti Klassik 22mm