Nomos Tetra 27 Review: Bauhaus Minimalism, Squared
Introduction
In 2025 I finally made the watchmaking pilgrimage to Glashütte for the 10th Glashütte Antique Watch Market and for the 180 year celebration of Glashütte Original and it felt like stepping into a living anthology of German watchmaking. Everywhere you turned there were pocket watches, early wristwatches and enthusiastic collectors quietly geeking out over movements and dials.
Right next to the German Watch Museum Glashütte I made sure to spend quality time at the Nomos store and that is where the Tetra 27 really clicked for me. The staff were genuinely warm, happy to pull out trays of square goodness and to let me linger a little too long over the tiny Tetra models (also got some Nomos branded playing cards for visiting their boutique that day).
What made the weekend even more special was that the market coincided with Glashütter ErlebnisZEIT, the town festival that fills the streets with local food stands, families and a very tangible sense of civic pride. Seeing how the town celebrates its watchmaking heritage on home turf gave the Tetra a different aura. Suddenly this quirky square dress watch was not just a minimalist design object but a distilled little piece of Glashütte culture on the wrist and I have been slightly obsessed with it since. I can now totally understand why Glashütte is at the forefront of German watch manufacturing.
A Case of compact Geometry
If you only know Nomos from the Tangente or Orion, the Tetra 27 is almost shocking in person. The case is a sharp little square of stainless steel measuring 27.5 by 27.5 millimeters, yet because of the geometry it wears more like a refined 33 millimeter round watch on the wrist. The lug to lug length of roughly 38.5 millimeters keeps things tidy and nicely proportioned, especially on slimmer wrists.
Thickness is where the Tetra 27 becomes properly addictive. At around 6.1 millimeters tall, aided by the wafer thin Alpha movement inside, it just glides under any cuff and almost disappears in profile. Short straight lugs and an 18 millimeter strap width balance the square form so the watch feels more like a little framed print than a blocky object. On the wrist in Glashütte, surrounded by big vintage chronographs, the Tetra felt almost mischievously svelte, like it knew it was the elegant outlier in a room full of tool watches.
The finishing is classic Nomos. You get a clean polished bezel, crisp case lines and a simple closed steel back that underlines the everyday dress watch intent. Water resistance is 30 meters, so this is very much a splash friendly but not swimming friendly companion, more at home with espresso bars and gallery openings than with deep sea adventures.
Dial and Hands that define Nomos
The Tetra 27 dial is one of those designs that looks almost too simple in photos and then charms you the moment light hits it. On this reference (Ref. 401) you get a galvanized, white and grey silver plated surface that has subtle warmth rather than sterile pure white. At the 6 o clock position a neat small seconds register provides just enough asymmetry to keep the square layout from feeling static.
Nomos goes for a mix of Arabic numerals and baton markers which gives the dial that signature Berlin school Bauhaus vibe while keeping legibility very clean. The numerals feel almost playful in the compact square frame. In Glashütte, under the softer museum district light, the printing looked razor sharp, exactly what you hope for at this price point.
The real treat though are the tempered blue steel hands. On the white silvered dial they dance between muted navy and electric blue depending on the angle, something that photos rarely capture properly (I caught myself doing the classic wrist roll more than once in the Nomos boutique). There is no lume and that is entirely in keeping with the dressy character. Instead the Tetra 27 leans into clean contrast and proportion so even with its minimalist vocabulary it remains easy to read at a glance.
Protecting everything is a flat sapphire crystal with anti reflective treatment that stays true to the watch’s angular silhouette while giving just a hint of distortion out at the very edge. It feels robust and modern without stealing the spotlight, which is exactly what you want here.
Movement: A Slim Manual Heart from Glashütte
Perhaps the biggest distinction lies under the hood. The Tetra 27 runs on the Nomos Alpha calibre, the brands first fully in house manual winding movement and still the backbone of many of their core lines. It beats at 21600 vibrations per hour, uses 17 jewels and delivers around 43 hours of power reserve, which means a quick wind every morning or every other morning keeps it happily ticking.
Alpha is impressively slim at about 2.6 millimeters high, which directly enables that 6.1 millimeter case thickness that makes the Tetra so compelling on the wrist. The movement architecture is pure Glashütte with the three quarter plate, blued screws and traditional finishing like ribbing and perlage giving it a quietly luxurious look even if this specific reference hides it behind a closed back.
In terms of performance, Alpha is built for daily reliability rather than spec sheet fireworks. The calibre is widely reported to run close to chronometer standards when well regulated and Nomos has been refining it continuously since its introduction in 2005. Winding the crown on the display piece in Glashütte felt smooth and precise, with just enough tactile feedback to make the ritual satisfying without feeling stiff (yes, my inner watch nerd was very happy).
Strap and Everyday Wearability
Nomos pairs the Tetra 27 with a black Horween Genuine Shell Cordovan leather strap and this is a big part of why the watch works so well as a daily minimalist companion. Shell Cordovan has that unique dense yet supple feel, and as it breaks in you get this glossy, almost ceramic sheen that plays nicely with the polished case. It also makes the Tetra feel more grown up than the 27.5 millimeter dimensions might suggest.
The strap is 18 millimeters at the lugs and tapers toward a simple polished stainless steel pin buckle that echoes the overall minimal design. With the compact lug to lug, the strap drops cleanly around the wrist so there are no awkward overhangs or stiff spots, which makes this a fantastic choice if you have a smaller wrist or just prefer understated proportions.
On the streets of Glashütte during ErlebnisZEIT, it struck me how naturally the Tetra 27 fits into a lifestyle that flows between museum visits, coffee breaks and dinner with friends. It is absolutely a dress leaning piece, but the Bauhaus design and robust everyday strap give it enough versatility to handle smart casual days effortlessly. This is not a watch that screams for attention. It is the one that rewards the person who actually takes the time to look (which seems fitting for a watch, really).
Why the Nomos Tetra 27 is Special
For such a small square, the Tetra 27 packs a surprising amount of character. Here is what makes it stand out in a crowded field of dress and design forward watches.
- Minimalist Bauhaus design with real provenance: The square case, clean typography and restrained color palette give you textbook Bauhaus vibes, but here they are anchored in genuine Glashütte manufacture know how rather than just surface level styling.
- Ultra thin, genuinely wearable proportions: At 27.5 by 27.5 millimeters and just over 6 millimeters thick, powered by a 2.6 millimeter high in house movement, the Tetra 27 offers a wearing experience that many larger watches simply cannot match.
- True in house manual movement: The Alpha calibre is not a rebranded generic movement. It is a home grown Nomos creation with traditional Glashütte finishing, 43 hour power reserve and a reputation for accuracy that punches above its price class.
- High quality strap straight out of the box: The black Horween Shell Cordovan strap adds tangible luxury and long term durability, making the watch feel more special the more you wear it instead of begging for an immediate strap upgrade.
- A tangible link to Glashütte culture: Worn in the town where it is made, a few minutes walk from the German Watch Museum and the Antique Watch Market, the Tetra 27 feels like a quiet ambassador for contemporary German watchmaking and a very accessible way into that world.
Conclusion
The Nomos Tetra 27 is a deceptively simple watch that reveals more the longer you spend with it. Between the ultra slim case, characterful square dial, honest in house Alpha calibre and that wonderfully supple Shell Cordovan strap, it offers a very coherent vision of what modern German dress watchmaking can be.
With pricing around 1820 euro before any regional variations, the Tetra 27 sits in a segment where many brands still rely on off the shelf calibres and more generic design languages. Here you get a full Glashütte manufactured movement, a distinct aesthetic and a strong sense of place, which feels like solid value if you love the idea of wearing a squared off slice of German watch culture. This is the kind of watch that will quietly keep time while reminding you of the day you strolled through Glashütte with the entire town celebrating watches and time, and that might be its most charming complication of all.
Specifications:
Brand – Nomos Glashütte
Model – Tetra 27 Reference 401
Case Material – Stainless steel, polished
Case Dimensions – 27.5 x 27.5 mm, approx. 6.1 mm thickness, 38.5 mm lug to lug, 18 mm lug width
Water Resistance – 30 m 3 ATM
Strap – Black Horween Genuine Shell Cordovan leather with stainless steel pin buckle (other options include Bracelet and Bracelet Sport, both in 18mm)
Crystal – Sapphire crystal with anti reflective treatment
Movement – Nomos Alpha, in house manual winding calibre, 17 jewels, 21600 vph, approx. 43 hour power reserve, Glashütte three quarter plate architecture
Power Reserve – Approximately 43 hours
Limited Edition – No
Lume – No
Price – €1820 approximately, depending on retailer and region
Official store link here.
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About Nomos Glashütte Tetra 27: Key Questions Answered
Is the Nomos Tetra 27 too small for a mens wrist?
Because of its square shape and 38.5 millimeter lug to lug length, the Tetra 27 wears a bit larger than the raw 27.5 millimeter width suggests and works very well on slimmer to medium wrists.
Can you swim with the Tetra 27?
The watch is rated to 30 meters of water resistance, which is fine for occasional splashes or getting caught in the rain but not intended for swimming or showering.
How often do you need to wind the Alpha movement?
With a power reserve of around 43 hours, winding the Tetra 27 once a day or every other day keeps it running happily and also gives you that small daily mechanical ritual.
