World’s ‘most complicated’ wristwatch unveiled

The new timepiece by Vacheron Constantin, unveiled at the 2025 Watches and Wonder trade fair in Geneva, offers a record-breaking 41 functions. (Vacheron Constantin via CNN Newsource)

It tracks the sun’s position in the sky. It chimes with the sound of hammers hitting four miniature gongs. It even tells the wearer when certain stars will be visible from Earth.

Swiss watchmaker Vacheron Constantin’s latest timepiece is not just packed with novel features — it is, officially, the most complicated mechanical wristwatch ever produced.

In horology, a “complication” refers to any function that goes beyond standard time-telling, such as a Gregorian calendar or moon phase display. And Vacheron Constantin’s new Les Cabinotiers Solaria Ultra Grand Complication contains a record-breaking 41 of them.

The one-off design, which went on show at the Watches and Wonders trade fair in Switzerland on Tuesday, comprises 1,521 separate components. The watchmaker is seeking to protect its new creation through 13 patent applications, seven of which relate to the chiming mechanism.

Seen by CNN during a fair preview, the watch presents three different measures of time: A conventional 24-hour-day, the sidereal time (the time taken for Earth to spin on its axis, which is around four minutes shorter than a calendar day) and the solar day (which is adjusted for the Earth’s elliptical orbit).

Among the dozens of other complications are astronomical functions tracking the sun’s position, height, trajectory and angle relative to Earth’s equator. A rotating display featuring the zodiac’s 13 constellations can meanwhile be adjusted to show when those stars will next be visible in the sky.

The watchmaker said its record-breaking wristwatch was eight years in the making, describing it as a “masterpiece of innovation.” The single-model watch’s case is made from 18-karat white gold and contains over 200 jewels, including several sapphire discs.

Founded in 1755 and now owned by luxury conglomerate Richemont, Vacheron Constantin also holds the record for the most complicated pocket watch. The brand’s Berkley Grand Complication, unveiled last year, features 63 horological complications including a Chinese perpetual calendar displaying the complex lunisolar cycle.

But while this represents 22 more complications than those boasted by its latest creation, pocket watches can be considerably larger than wristwatches. At 45 millimeters (1.8 inches), the new Solaria Ultra Grand Complication’s case is less than half the diameter of the Berkley’s.

As such, the design challenge was also about fitting the watch’s functions into a case small enough to be comfortably worn on the wrist, according to Vacheron Constantin’s style and heritage director, Christian Selmoni.

In a press release describing the wristwatch as a “feat of miniaturization,” Selmoni said the brand’s horologists had arranged tiny components in the “most logical and compact way possible.”

“The main objective was to bring together all the main complications, timekeeping, calendar, chronograph and chiming, on a single base plate and to concentrate the astronomical functions on an additional plate,” he is quoted saying. “Thanks to this construction, it was possible to create a wristwatch with harmonious proportions.”