This Watch Is Thinner Than Your Credit Card!
A countdown of the 8 slimmest mechanical watches ever made—and the engineering madness behind them.
Watchmaking is often about making things smaller—smaller gears, slimmer movements, more discreet displays of craftsmanship. But over the past decade, brands have taken this to the extreme.
The race to create the thinnest mechanical watch ever made has turned into a silent arms race among elite maisons. Piaget, Bulgari, Richard Mille, Audemars Piguet, and Jaeger-LeCoultre have all stepped into the arena with marvels of micromechanics that make even a £1 coin seem chunky.
Today, we’re going to count down the 8 thinnest mechanical watches ever made, starting from the 8th and working our way to the current record holder. These watches aren’t just thin—they’re technological achievements, combining manual wind, automatic movements, and even complications into thicknesses thinner than a credit card.
Let’s begin.
#8 — Audemars Piguet Royal Oak RD#2
Thickness: 6.3mm
Movement: Caliber 5133 (automatic)
Price: ~$140,000 USD
Complications: Perpetual calendar
This isn’t just about thinness—it’s about thin complication. AP achieved the impossible by compressing a full perpetual calendar into 6.3mm of Royal Oak elegance. The rotor was redesigned to sit within the movement rather than on top of it. Not the thinnest on this list, but easily one of the most impressive.
#7 — Vacheron Constantin Historiques Ultra-Fine 1955
Thickness: 4.1mm
Movement: Caliber 1003 (manual, 1.64mm thick)
Price: ~$30,000 USD (discontinued)
Complications: Time-only
The most classic piece on the list. Vacheron’s 1955 tribute uses Caliber 1003, a movement designed in the 1950s that still ranks among the thinnest ever made. Elegant, understated, and museum-worthy in its simplicity.
#6 — Piaget Altiplano 900P
Thickness: 3.65mm
Movement: Caliber 900P (manual)
Price: ~$25,000–30,000 USD (discontinued)
Complications: Time-only
This 2014 milestone broke barriers. The movement isn’t mounted in the case—it is the case. Piaget merged the movement baseplate and caseback into one unified structure, removing layers and breaking records. A huge step forward for ultra-thin design.
#5 — Jaeger-LeCoultre Master Ultra Thin Squelette
Thickness: 3.6mm
Movement: Caliber 849ASQ
Price: ~$60,000 USD
Complications: None — time-only, skeletonized
A classic from the brand often called the watchmaker’s watchmaker. The Master Ultra Thin Squelette combines elegance with extreme watchmaking finesse. It’s hand-engraved, fully skeletonized, and has one of the thinnest manually wound movements ever made. This is haute horlogerie at its most delicate.
#4 — Piaget Altiplano Ultimate Concept
Thickness: 2.00mm
Movement: Integrated manual-wind architecture
Price: ~$450,000 USD (bespoke only)
Complications: Time-only
Piaget shocked the world in 2020 with a watch that didn’t look like it should even work. Nearly every component was re-engineered, some gears shrunk to 0.12mm thick—thinner than a human hair. Even the crystal is just 0.2mm thick. It’s not water-resistant, and winding it is nerve-wracking, but it’s art.
#3 — Bulgari Octo Finissimo Ultra
Thickness: 1.80mm
Movement: Caliber BVL180 (manual)
Price: ~$440,000 USD (limited to 10 pieces)
Complications: Time-only, digital QR code linked to NFT
With its sandblasted titanium design and QR code on the mainspring barrel, this piece looked like it came from 2099. The watch’s gear train is spread out rather than stacked, and every component had to be built from scratch. A total of just 10 units were made. Exclusive, experimental, and daring.
#2 — Richard Mille RM UP-01 Ferrari
Thickness: 1.75mm
Movement: Caliber RMUP-01 (manual)
Price: ~$1,888,000 USD
Complications: Time-only
If you’re wondering what happens when Richard Mille and Ferrari go on a diet together—this is it. It’s razor-thin, but unlike most ultra-thins, it’s shockproof, water-resistant, and practically bulletproof by comparison. It even passed 5,000G crash tests. Engineering meets motorsport madness.
#1 — Bulgari Octo Finissimo Ultra COSC (2024)
Thickness: 1.70mm
Movement: BVL180 COSC-certified (manual)
Price: TBA / Likely above $500,000 USD
Complications: Time-only
And we have a new king. Bulgari reclaimed the crown in 2024 with this COSC-certified version of its Ultra watch. Not only is it thinner—it’s officially accurate to chronometer standards. That means it's both ridiculously slim and reliably precise. Expect just a handful of pieces to be made.
To put this into perspective: the average Apple Watch is 10.7mm thick. This is 1/6th of that.
I have to loose some weight first before buying.