The topic of watch dimensions is pretty hot in the watch industry at the moment. Well, not just at the moment. People have been arguing over oversized watches for years now, whether it is Panerai’s dinner plates, Hublot’s spaceship-sized chronographs, or that one guy who somehow still believes a 47mm diver is “perfectly wearable.” But what has genuinely become interesting over the last few years is not how brands are making watches bigger, it is how they are making them smaller.

Because let us be honest for a second. The industry spent almost two decades inflating dimensions to absurd levels before collectively realizing that maybe not everyone wants a freaking boat strapped to their wrist. And yes, size is relative. A 42mm Panerai Luminor does not wear like a 42mm Royal Oak Offshore, and neither wears like a 42mm dress watch with long lugs and a thick bezel. But regardless of how subjective wrist presence can be, the broader industry trend is undeniable: collectors want smaller watches again. As well as skinny fashionistas, but let’s leave those alone for now…

What most people fail to understand, however, is that shrinking a watch is not a matter of scaling down a drawing and calling it a day. A smaller watch is a completely different watch mechanically, structurally, and proportionally. The amount of engineering required to remove a few millimeters from a case diameter can be absurd, especially once you enter the world of integrated bracelets, ultra-thin calibers, or complicated movements. Which we’re getting into in this article.

I took some time to get this article done because I have always loved concepts that appear incredibly simple at first, until you begin understanding the absurd amount of effort hiding behind them. And in this case, that concept is simply making a watch smaller. 

Bulgari’s new Octo Finissimo 37 from Watches and Wonders 2026 is probably the best recent example of this phenomenon. From the outside, it looks deceptively simple. Bulgari took the Octo Finissimo Automatic, one of the defining luxury sports watches of the last decade, and reduced its size from 40mm to 37mm. Sounds easy enough. Except the project reportedly took three years to develop, required an entirely new movement, and forced Bulgari to rethink the watch from the inside out.

The reason is actually quite simple once you understand how movement architecture dictates case dimensions. The original Octo Finissimo Automatic used Bulgari’s BVL 138 caliber, a movement measuring roughly 36.6mm across. That movement occupied nearly the entire footprint of the original case, which is one of the reasons why the proportions on the larger Octo Finissimo feel so balanced. There is no wasted space inside the watch. The movement and case were designed almost as one continuous structure.

Now imagine trying to shrink that case by three millimeters while keeping the same movement. Suddenly everything falls apart. The bezel becomes too thin, the dial spacing awkward, the crown placement compromised, and the structural integrity of the case increasingly difficult to maintain. Bulgari could not simply make the watch smaller because the movement itself physically dictated the minimum possible dimensions of the watch.

So instead of resizing the old caliber, Bulgari engineered a completely new one. The new BVF 100 movement measures approximately 31mm in diameter and took around three years to develop. Interestingly, while the movement is smaller horizontally, it is actually slightly thicker than the previous caliber. This means the new Octo Finissimo 37 is smaller in diameter while simultaneously becoming thicker overall than its predecessor, which sounds contradictory until you realize that miniaturization in watchmaking is rarely linear. Removing horizontal space often forces compromises vertically because gear trains, automatic winding systems, shock protection, and structural rigidity still need somewhere to exist.

Even more fascinating is the fact that Bulgari reportedly carried over only two components from the previous movement: the platinum micro-rotor and the balance wheel. Everything else had to be redesigned. That is an extraordinary amount of work for what the average person would describe as “the smaller version.”

“Small” is not just horizontal, it’s also vertical. Thinness I mean. And the moment thinness enters the conversation, things become even more insane.

Because making a watch thinner eventually forces brands to abandon traditional watchmaking architecture altogether. Bulgari’s Octo Finissimo Ultra Tourbillon from 2025 is one of the clearest demonstrations of this. At just 1.85mm thick, the watch essentially stops functioning like a conventional wristwatch from a construction standpoint. The movement and the case become integrated into a single structural system because there is physically no room left for traditional layering. The caseback itself acts as the movement’s mainplate, conventional crown systems disappear in favor of lateral adjustment wheels, and every component must be reconsidered under the terrifying reality that fractions of a millimeter now determine whether the entire watch functions or not.

Piaget ran into the exact same engineering nightmare with the Altiplano Ultimate Concept. At extreme levels of thinness, problems that barely exist in conventional watchmaking suddenly become critical. Crystals flex under pressure. Lubrication becomes more difficult because tolerances become microscopic. Shock resistance becomes dramatically harder to guarantee. Even the hands themselves become engineering challenges because traditional hand stacks occupy too much vertical space.

And this is where many collectors underestimate the significance of ultra-thin records. People love mocking brands for celebrating reductions of 0.2mm as if they are meaningless marketing exercises, but that tiny reduction may require years of research and entirely new manufacturing techniques. In modern horology, a tenth of a millimeter can represent a complete reinvention of the watch’s architecture.

What makes the whole conversation even more complicated is the fact that proportions are often harder to preserve than dimensions themselves. The Omega Speedmaster Reduced is a perfect example of this issue. Omega wanted a smaller version of the Speedmaster Professional, but instead of redesigning the Moonwatch caliber from scratch, the brand opted for a modular automatic chronograph movement. Technically speaking, the watch succeeded in becoming smaller. Visually, however, the differences became immediately noticeable because the subdials shifted outward due to the new movement architecture. The watch also became thicker than many expected because the chronograph module was stacked on top of the base movement.

This is something enthusiasts often forget: dial layouts are not arbitrary design choices. Subdial placement, spacing, symmetry, and visual balance are heavily dictated by movement geometry. You cannot simply “move things around” because wheels, pinions, and chronograph systems physically determine where indications can exist. That is why shrinking complicated watches is so difficult. The smaller the canvas becomes, the harder it is to maintain visual harmony without redesigning the movement entirely.

Integrated bracelet watches add another layer of complexity altogether because the bracelet itself becomes part of the watch’s architecture. Cartier understood this very well with the modern Santos Medium. A watch I don’t particularly favor, but hey, gotta give them their flowers. Square watches naturally wear larger than round watches, and integrated bracelets dramatically affect perceived size, so the brand focused heavily on ergonomics, bracelet flexibility, and overall wrist integration rather than merely reducing measurements on paper.

The same challenge exists for watches like the Vacheron Constantin Overseas or the Octo Finissimo. Once a bracelet is integrated into the design, resizing the watch means recalculating everything from the first center links to the taper, the articulation angles, and even the visual stance of the watch on the wrist. A luxury sports watch can very quickly lose its identity if proportions are not handled carefully. Rolex encountered this balancing act with the Yacht-Master 37, which had to remain visually recognizably “Rolex sports watch” despite reduced dimensions. Too small and the watch loses presence. Too thin and it stops feeling robust. Too compact and the sporty character disappears entirely.

And perhaps the most ironic part of all this is that smaller movements are often harder to make accurate. Omega openly discussed the challenges involved in developing smaller Master Chronometer calibers for the Aqua Terra 30mm collection because reduced dimensions create lower inertia, tighter tolerances, less shock stability, and significantly less room for gear trains and regulating systems. In other words, miniaturization actively works against chronometric stability.

Which completely destroys the assumption that smaller watches are somehow easier to engineer.

If anything, the opposite is true. Modern watchmaking has reached a point where making a watch smaller often requires more innovation than adding another complication. A perpetual calendar can be difficult, of course, but preserving proportions, thinness, reliability, water resistance, ergonomics, accuracy, and visual identity while reducing dimensions may be one of the hardest balancing acts in contemporary horology.

And honestly, that is why this entire trend fascinates me so much. Beneath the surface-level discussion of whether 36mm or 40mm is the “perfect size” lies something genuinely interesting: brands are once again being forced to innovate mechanically because it’s aesthetically better. They are redesigning movements, rethinking structures, and pushing limits simply to make watches more wearable.

I’m as much of a hater as the next watch snob. But the next time a brand announces a watch that is 2mm smaller or 1mm thinner, understand that somewhere behind that release are probably years of failed prototypes, insane architectures, redesigned movements, and engineers losing sleep over microscopic tolerances that most people will never even notice.

And that, to me, is the kind of insanity that makes horology so brilliant.