We spent a good, long time covering Omega’s interesting chronographs from the 1970s, so now it’s time to shine the light elsewhere. Today, we’re looking at Heuer, and their slide rule-clad chronograph, the Heuer Calculator. While the Breitling Navitimer is probably the best-known mechanical watch with a slide rule bezel, the Heuer Calculator is arguably the coolest (and weirdest).
In the 1970s – while the US and USSR were in a nuclear arms race – Heuer, Omega, and Breitling seemed to be having their own arms race (wrists race?), one of funky chronographs. Introduced in 1972, the Heuer Calculator is much more badass than your standard Ti-83. Although it might take an engineering degree earned 40 years ago to understand, the utility of a mechanical calculator is just plain awesome. If you were looking for a zombie apocalypse watch, this might be the one – just make sure you have a watchmaker in your group of survivors to keep it running.
1970s era Heuer catalog showing the Calculator in both dial colors
Standing at a beefy 45mm in diameter and 15.5mm thick, there’s no forgetting the Calculator is on your wrist. It’s big, and it wears big. It essentially looks like a cushion case Autavia took a heavy dose of steroids, and donned a busier bezel. The two-register subdial layout is there, and the orange hands are very recognizable for ’70s Heuers. You’ll mostly find black dial Calculators (with and without orange accents), but Heuer also produced a blue dial version. Over its decade-long run, the Calculator was powered by the calibers 15 and 11, and the Valjoux 7740 – all of which place the crown on the off side of the case to the pushers. I love this crown/pusher configuration, not really for any practical reasons, but because it looks cool.
As for that bezel, you’ll notice the major difference between Breitling’s slide rule and the Heuer Calculator’s is that it’s on the outside. The large external bezel is actually split, allowing the inner part to stay still while the outside part can be rotated to its correct calculating position. If you’re curious about how to read the bezel, the late Chuck Maddox posted a great guide on his (invaluable) website many years ago: Breitling Navitimer Instructions. While there are slight differences between the Heuer and Breitling in terms of units displayed, the concept for the slide rule is the same. We won’t judge you if you end up cross-eyed and reaching for your smartphone after a few paragraphs.
Although there isn’t a tremendous amount of information out there on the Calculator, second-hand prices for them have been on the rise. The original retail on these beasts topped off just under $300, and you can safely add a zero to that for today’s value. Nice examples are out there, and we think they’re a great pickup for any collection. Like any vintage watch, be on the lookout for re-done dials and replaced hands and other parts. A good example should be worth the $3,000 when compared to ‘70s Autavias, Carreras and Camaros with similar movements. Too many cool 1970s chronographs, not enough time and money.
Feature photo courtesy of Chronocentric.com.
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