A fully functioning Seiko Calculator watch which is very retro, and on the original bracelet.  Model reference C359-5000


From the serial number on the case back we can accurately date this watch to being made in November 1979.  The C359-5000 was launched in May that year


When Seiko launched their second generation calculator watch it had a suggested retail price of £105.  To put that into context, using the Bank of England’s inflation calculator that would be £535 today, so the hype about students cheating in exams using calculator watches wasn’t really an issue.  The other things is the calculator is difficult to use – you need to use a stylus or toothpick, and the buttons are small.  What is not helped is that the graphics showing what button does what have all disappeared from this example.  We have checked that every button works, including the pushers.  The alarm works too, which is rare, although the light doesn’t.  The glass does have a few light scratches, which is common with these, but there is no LCD bleed across the screen and no missing segments on the numbers either.  This is a better than average example.

There is an interesting article here about the top 15 calculator watches – purely subject by the author like all these things, but some interesting variants.

This watch will be supplied with our branded presentation box and our Certificate of Authenticity.

Please see the HD video for more detail.  All photos and videos are part of the description and are of the actual watch unless mentioned.  We do not photoshop any pictures, and the images are copyright of birthyearwatches.com and should not be used without permission.


Width with crown  34.5 mm

Width without crown  34.5 mm

Between lugs  20 mm

Lug to lug length  37.7 mm

Case Thickness  9.2 mm

Bracelet will fit a maximum wrist size of 225 mm.  The bracelet can be sized easily without the need for special tools.

All sizes are approximate.

Included with this watch is a 1 month guarantee and free delivery to UK addresses.  If you live outside the UK we can still deliver to most countries.  Please see our Worldwide Shipping information, or Contact Us.   Payment can be made by most credit or debit cards, bank transfer or PayPal.

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