Rectangular and square watches break with the round case that most wristwatches use, and that's why they stand out on the wrist. This guide covers what collectors call the different shapes, which watches came first, the rugged square models that became cult classics, and the vintage Omega, Longines and Jaeger-LeCoultre pieces we see most in our shop.
A rectangular watch is longer than it is wide. Collectors call it a tank after the Cartier Tank of 1917, and you'll see rectangular watches from other brands sold as tank style watches. A square watch has equal sides. The Cartier Santos of 1904 is the best-known early square wristwatch.
For rectangular and square vintage watches under $3,000, look at 1930s Omega and Longines tanks and the Omega De Ville squares of the 1960s. For an icon, the Jaeger-LeCoultre Reverso of 1931 is still in production today.
Customers who buy a rectangular watch from us rarely go back to round ones. The shape changes how a dress watch sits under a cuff, and a 1930s tank looks right with a suit in a way a round watch of the same size doesn't.
What Are Rectangular and Square Watches Called?
Watch collectors use a handful of names for non-round cases, and each one describes a slightly different shape. You'll see these terms in our listings and in auction catalogues.
| Name | Shape | Example |
|---|---|---|
| Tank | Rectangular, with the lugs built into the sides of the case | Cartier Tank, Omega and Longines Art Deco tanks |
| Square | Equal height and width | Cartier Santos, Omega De Ville squares |
| Tonneau | Barrel-shaped, with curved sides | Omega Genève tonneau of the 1970s |
| Cushion | Square with rounded corners | Raketa "TV" watches, Omega De Ville cushion |
| Curvex | Rectangular, bent along its length to follow the wrist | Gruen Curvex, 1930s Omega tanks |
| Reversible | Rectangular case that flips over on its frame | Jaeger-LeCoultre Reverso |
"Tank" has become the general name for any vintage rectangular watch, whatever the brand. When a listing says "Omega tank" or "Longines tank", it means a rectangular Omega or Longines, and the name is a nod to Cartier.
Rectangular vs. Square: The Difference on the Wrist
Both shapes belong to the same family, but they wear differently. A rectangular case runs along the wrist and looks slim, so it suits a dress watch worn under a cuff. A square case has the same width and length, so it sits wider and gives the watch more presence.
Size works differently too. A 1930s tank of 22mm across can measure 38 to 40mm from lug to lug, and on the wrist it looks bigger than its width suggests. A square watch of 30mm covers more of the wrist than a round watch of the same width, because the corners fill the space a circle leaves empty.
The First Rectangular and Square Watches
The first famous square wristwatch came from Cartier. Louis Cartier designed the Santos in 1904 for his friend Alberto Santos-Dumont, a Brazilian aviator who wanted to read the time without taking his hands off the controls. Cartier put the watch on general sale in 1911, according to Wikipedia's history of the Cartier Santos.
The rectangular watch followed. Louis Cartier designed the Tank in 1917, taking its shape from the tanks of the Western Front, and full production began in 1919. Its success set the template that Omega, Longines and nearly every other Swiss brand followed through the Art Deco years of the 1920s and 1930s.
Those decades produced stepped and curved cases, sector and two-tone dials, and small hand-wound movements shaped to fit a narrow case. Jaeger-LeCoultre added the Reverso in 1931, and Omega used a rectangular case for its Marine diver's watch in 1932.
Rugged Square Watches That Became Cult Classics
Square and rectangular watches aren't only dress watches. A few tough designs built a following that has lasted for decades, and three of them are still in production.
Omega Marine (1932)
Omega's Marine had a rectangular case that slid inside a second outer case, which sealed the watch against water. It's one of the earliest diver's watches sold to the public. Its descendant, the rectangular Marine Standard, ran on Omega's T17 movement, and we have a 1939 example in our shop.
Heuer Monaco (1969)
Heuer launched the Monaco in 1969 as a square, water-resistant automatic chronograph powered by the Calibre 11. Steve McQueen wore one in the 1971 film Le Mans, and that film made the Monaco the best-known square sports watch. TAG Heuer still makes it.
Casio G-Shock DW-5000C (1983)
Casio engineer Kikuo Ibe designed the first G-Shock to survive a fall and a knock. The DW-5000C of 1983 has a square resin case, and its shape has stayed almost unchanged in Casio's range ever since.
Cartier Santos (1904)
The Santos started as a tool for a pilot, with screws on the bezel that later became its signature. Cartier still makes it, now with a steel bracelet and sporty proportions.
Are Square and Rectangular Watches in Style?
Yes. Cartier still makes the Tank and the Santos, Jaeger-LeCoultre the Reverso and TAG Heuer the Monaco, which shows that the big brands keep these shapes in their main collections. Longines also still sells a rectangular collection, the DolceVita.
Men wear square watches as readily as women, and the size decides how the watch looks. A larger square such as an Omega De Ville or a Monaco suits an average man's wrist. A small 1930s tank of 20 to 22mm works on a man as a slim dress watch or on a woman as an everyday piece.
Omega
Omega made rectangular and square watches from the 1920s to the 1990s. The Art Deco tanks of the 1930s use the hand-wound caliber T17, and their dials range from black gilt and chocolate brown to white, silver and sector layouts. The De Ville line of the 1960s to 1980s added square and rectangular cases with cleaner dials, from the hand-wound ref. 511.0378 to the quartz ref. 395.0877.
We've listed 61 Omega tanks so far. Our guide to vintage Omega tank watches goes through the models in more detail.
Longines
Longines made rectangular and square watches from the 1920s through the 1990s, and its pre-war tanks are some of the best value in vintage rectangular watches today. You'll find them in our vintage Longines collection.
Pre-War Longines Tanks (1920s–1940s)
The 1930s Longines tanks come with a wide range of dials. We've had sector dials, black gilt dials with gold printing, two-tone dials with an outer scale for doctors to take a pulse, and plain white and silver dials with Arabic numerals or applied markers.
Longines used Staybrite steel for some of its 1930s cases, a stainless alloy that resists corrosion well, and gold-plated cases for its more affordable models. Inside, small hand-wound calibers such as the 20.28, 9.32, 9L and 2517 fit the narrow cases. Our 1934 sector-dial tank with the 20.28 measures 22 by 38mm, and our 1933 doctor's tank with the 9.32 measures 20 by 38.5mm.
Longines Rectangular and Square Watches (1970s–1990s)
From the 1970s Longines moved its rectangular watches to quartz and slimmer cases, and it added elliptical cases to the range. The dials of this period carry textures such as linen weaves, stripes, fine grids and sunburst finishes, in gold, champagne, cream and ivory tones that match the gold-plated cases.
The St. Moritz is the best-known family of the period. It has a slim gold-tone rectangular case, on a leather strap or an integrated bracelet, and buyers now look for it as an alternative to a Cartier Tank. Our guide to vintage Cartier Tank alternatives compares it with other rectangular watches.
Jaeger-LeCoultre
Jaeger-LeCoultre built the most famous rectangular watch after the Cartier Tank. Its Reverso dates from 1931, when British officers playing polo in India needed a watch that could survive a match. The patented case slides and flips over on its frame, so the crystal faces the wrist and the metal back takes the knocks.
Over the decades the Reverso grew into a family: small 1930s originals, the slim Classique, the larger Grande Taille, dual-time Duo models and smaller Lady versions. Jaeger-LeCoultre also made other rectangular watches in the 1930s and 1940s, such as the Uni-Plan, with a slim case and a small hand-wound movement. Our vintage Jaeger-LeCoultre collector's guide covers the brand in depth.
What to Check Before Buying
A vintage rectangular watch needs a few checks that a round one doesn't. These are the ones we run first.
- The crystal. Rectangular and curved crystals are harder to replace than round ones, so check for cracks and a tight fit.
- The corners of the case. Plating wears through first on the corners and edges, so look there for brass showing through on a gold-plated or gold-filled case.
- The dial. Sector and two-tone dials lose value when someone refinishes them. Look for crisp printing and aging that matches the hands.
- The size. Check the length from lug to lug as well as the width. A 22mm tank that measures 40mm long wears far bigger than its width suggests.
Our 1930s Omega and Longines tanks with sector or black gilt dials sell faster than any other rectangular watches we list. Buyers forgive wear on the case of a 90-year-old tank, but they want the dial original.
We measure every tank from lug to lug as well as across, and we put both numbers in the listing, because the length tells you more about how the watch will wear.
Rectangular Watches We've Sold
Every watch we list stays on our site after it's sold, so you can still see the photos and details. These rectangular watches have found new owners.
Omega · Cal. T17 Chocolate Copper Dial Sold for $2,275 
Omega · Cal. T17 Rectangular Tank, 1930s Sold for $2,160 
Omega · Cal. T17 Black Gilt Dial, 1930s Sold for $2,000 
Jaeger-LeCoultre · Cal. 413 Uni-Plan Model J, 1940s Sold for $2,732 
Longines · Cal. 9.32 Doctor's Tank, 1933 Sold for $1,372 
Longines · Cal. 20.28 Sector Dial Tank, 1934 Sold for $1,178
Your Questions Answered
Frequently Asked Questions
What are rectangular watches called?
What was the first rectangular watch?
Are square watches in style?
Which rugged square watches became cult classics?
Do men wear square watches?
Which brands made the best-known rectangular watches?
What is the difference between a square and a rectangular watch?
Which iconic square watches are still in production?
