About Watch the Details
A reference for the watch you already own: the battery it takes, the movement inside, its real size and the parts that fit it, with the document behind every number.
Why it exists
Most questions about an everyday watch start with a code: the number on the old battery, the calibre on the movement, the reference on the case back. The answers exist, but they are spread across makers’ PDFs, cross-reference charts, forum threads and shop listings, and the numbers in them often disagree by a millimetre or a code.
This reference puts those answers in one place and keeps them connected. A model page points to its movement; the movement to its battery; the lugs to the strap width. Each number on the way carries a footnote to the document it came from and the date it was checked, so you can see where it stands before you order a part or open a case.
What is in it
Today the data holds:
- 45 battery sizes with the codes different makers print for each, so 377, SR626SW, SB-AW and 280-39 lead to the same page. Batteries
- 137 movements from 7 makers, including Seiko and TMI NH calibres, Miyota, ETA, Sellita, Casio modules and Citizen calibres. Movements
- 203 watch models from Seiko, Casio, Citizen, Spinnaker, Zelos, Dan Henry, Islander, Vostok-Europe, Addiesdive, with their sizes, movement, battery and strap. Watches
- Serial-number rules for 4 brands, and calculators for wrist fit, size comparison, strap size, accuracy and battery swaps. Tools
The battery, movement and watch pages above make 385 reference pages. Behind them sit 5,357 sourced facts and 5,491 rows from the makers’ own tables, citing 646 documents. Coverage starts with Seiko, Casio and Citizen, the brands owners ask about most, and the movements used across many brands.
How it is made
Numbers are copied from primary documents first: battery makers’ datasheets, movement makers’ spec sheets and drawings, watch brands’ manuals and product pages. Where those are silent, a measured review or a parts seller can fill the gap, and the page says so next to the number. Nothing is averaged or guessed; a number with no source reads “not published”. The full rules are on How we source numbers.
Drawings on the site are generated from those numbers, to scale, and labelled as drawings. The photographs that set the scene on some pages are AI-generated illustrations. Each image file carries a machine-readable AI label, and they never stand for a particular watch or movement.
Independence
Watch the Details is not affiliated with Seiko, Casio, Citizen, TMI, Miyota, ETA, Sellita or any other maker named on it. Brand and model names are used only to identify watches and parts. We do not sell watches, rate them, or check whether one is genuine. If shop links are added later, they will be marked as such and will never change which number a page shows.
Getting in touch
Found a number that does not match your watch or its document? The quickest fix starts on Corrections. Contact details will be published when a mailbox is ready; see Contact.