The Thinnest Mechanical Watch in the World Measures Just 1.75 Millimeters Thick

Richard Mille took the watch world by surprise with this new record-breaker.

worlds thinnest watch Richard Mille

If you’ve got a United States quarter on hand, pull it out and have a look: that’s what 1.75mm-thick metal looks like. And it’s the same thickness as the new thinnest watch in the world: the Richard Mille RM UP-01 Ferrari.

The new champion in this horological race was decided by fractions of a millimeter. When, just a few short months ago, Bulgari announced the record-breaking world’s thinnest watch at 1.8mm, the Richard Mille team’s reaction must’ve been one of quiet elation; they had a trump card up their sleeves, as the RM UP-01 had been in development for years — and it was 0.05mm thinner. That’s a difference of 50 microns, the equivalent of two white bloods cells next to each other. The previous record was held by Piaget for a watch that was a still impressive 2mm thick.

worlds thinnest watch
The Richard Mille RM UP-01 weighs only 30g on the wrist, strap included.
Richard Mille

There’s a lot of engineering and development that goes into these mechanical marvels, but a big part of the solution for Piaget and Bulgari was to incorporate the movement’s foundational structure (the mainplate) into the watch’s caseback itself. It’s interesting that Richard Mille took a different approach and managed to achieve this thinness while using a (relatively) “traditional” case structure, sandwiching the movement between a titanium caseback and bezel. (The movement itself is only 1.18mm thick.)

Even more impressive is the reason they did this, and the result they achieved: durability. It’s a tenet of Richard Mille watches that despite their exorbitant prices and intricate innards, they should be highly robust and suitable for actual wear — as regularly proven by athlete ambassadors like Rafael Nadal who plays professional tennis with such watches on his wrist. The Richard Mille RM UP-01 might be wafer-thin, but it’s tested to withstand over 5,000 Gs of acceleration, around 77 times what would kill an average human. (Though, it’s not very water-resistant, at only 10m).

worlds thinnest watch
Over 6,000 hours of development and testing went into creating the Richard Mille RM UP-01 watch.
Richard Mille

The primary reason watchmakers have long strived to make thinner watches (aside from claiming records)? Comfort. Richard Mille watches are typically boldly proportioned but impressively ergonomic, so an extra-thin one should be even more so. The RM UP-01 measures 39mm long and 51mm wide and, despite seeming to break entirely new ground for the brand in a few ways, it maintains familiar design cues like its tonneau case shape and prominent bezel screws.

Though nothing about developing such a watch is simple, the RM UP-01 is functionally basic, displaying only the hours and minutes on a small dial. The crown for winding and setting has been integrated into the bezel’s plane, too, as has a separate mode selector for it. The wearer is also greeted by a view of the balance wheel through a 0.2mm sapphire crystal and beneath it is a Ferrari logo — the watch having been announced to celebrate a partnership with the carmaker.

worlds thinnest watch
The “UP” in the RM UP-01 watch’s name stands for ultra plat, or “ultra thin” in French.
Richard Mille

Watches such as these serve to show what a brand is capable of, and they’re not really the kind of products average people can buy and wear. We’d like to see more watch brands competing for thin but economical and practical watches, but sometimes solutions found in the development of these halo products can trickle down to the rest of the industry. Even watch snobs who might have scoffed at Richard Mille’s typically brash and showy aesthetic will have to concede that this is impressive stuff.

The RM UP-01 is limited to 150 examples and will cost $1,888,000 — or just over a million dollars per millimeter of thickness.

,