watch.bid
Know your watch, inside and out.
Tools for watch owners and collectors. 3 free tools that work in your browser — no sign-up, nothing to install.
- 1Read the serial on the case back
- 2Decode the year and month digits
- 3Match with the movement to get the date
Seiko serial number decoderFind the month and possible years your Seiko was made from the serial on the caseback.DecoderWatch battery cross-referenceSR626SW, 377, AG4… find every equivalent code for your watch battery.FinderWatch size & wrist fit checkerWill a 42 mm watch fit your wrist? Check case size, lug-to-lug and strap length.Fit checker
Why these tools
Built for real questions, not for clicks.
Each tool answers one practical question, shows its working, and links to the official source where rules or standards apply. Nothing you type is stored.