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Cartier Tank Size & Strap Guide
Cartier Tank Must vs Tank Solo
Few watches are as instantly recognisable as the Cartier Tank. Introduced in 1917 and inspired by the shape of military tanks viewed from above, the design has remained remarkably consistent for more than a century. The rectangular case, Roman numerals, railway minute track, and blued sword hands have become hallmarks of Cartier’s design language.
Over the years, Cartier has released many variations of the Tank. Two of the most commonly seen modern versions are the Tank Must and the Tank Solo. At first glance they look quite similar, but there are subtle differences in proportions, case construction, and strap compatibility that are important to understand if you are considering a strap change.
This guide compares the Tank Must and Tank Solo sizes, explains their lug widths, and helps you understand what straps will fit properly.
The Tank Must
The Cartier Tank Must is the modern evolution of the classic Tank line. It was introduced as the successor to the Tank Solo and carries forward the traditional aesthetic while refining the case design and finishing.
The Tank Must is available in three main sizes:
Small with a 16mm lug width
Large with a 19mm lug width
Extra Large (XL) with a 23mm lug width
These lug widths are relatively straightforward compared to many Cartier watches, but the Tank case introduces another factor that affects strap fit. The lugs are extremely short and integrated into the case design, which means strap thickness and construction matter more than on many other watches.
Because the lugs sit so close to the case, thicker straps can struggle to fit comfortably between them. Even when the width is correct, a strap that is too thick at the lug area can create installation issues or an awkward fit.
The Tank Solo
The Cartier Tank Solo preceded the Tank Must and remains widely owned. While visually similar, the case proportions and lug widths differ slightly.
The Tank Solo also comes in three main sizes:
Small with a 17.5mm lug width
Large with a 20mm lug width
Extra Large (XL) with a 22.5mm lug width
These lug widths are less conventional than the Tank Must. Sizes such as 17.5mm and 22.5mm fall between standard strap widths, which can make finding off the shelf straps more complicated.
As with the Tank Must, the short lug design means strap thickness at the attachment point becomes especially important.
Regular straps are hit or miss
Many owners assume that swapping straps on a Tank is as simple as matching the lug width. In reality, the Tank case design makes things slightly more complicated.
Because the lugs are very short and sit close to the case, regular leather or rubber straps may fit inconsistently. Even when the strap width matches the lug width, the thickness at the lug end can prevent the strap from sitting properly.
This becomes even more noticeable on the Tank Solo because of its unconventional lug widths like 17.5mm and 22.5mm. A standard 18mm or 22mm strap may sometimes fit, but the result can feel slightly tight or slightly loose depending on the construction of the strap.
For this reason, strap changes on the Tank Must and Tank Solo are often described as hit or miss when using standard straps.
Leather straps that work well
While custom straps provide the most precise fit, there are also several strap styles that tend to work well on both the Tank Must and Tank Solo when constructed correctly.
One example is the Slim Horween Chromexcel leather strap. Because of its slim profile and flexible leather, it pairs beautifully with the thin case of the Tank. In colours like burgundy and olive, it adds warmth and personality without overwhelming the watch.
The burgundy option gives the Tank a classic and slightly dressier feel, especially when paired with the Roman numeral dial and blued hands. The olive version introduces a subtle modern touch while remaining understated enough to suit the watch’s heritage.
Rubber straps that work well
Another popular option is the TrimFIT Mosaic strap. These straps bring a more contemporary aesthetic while maintaining a sleek and structured profile that works with the Tank’s geometry.
Colours like yellow and turquoise can completely transform the character of the watch. Instead of a purely formal piece, the Tank becomes a playful and expressive accessory that still retains its iconic design.
Because the TrimFIT Mosaic straps are designed with a streamlined profile, they sit comfortably between the short lugs without looking bulky.
Custom leather for a perfect fit
For those who want something truly distinctive, a custom leather strap remains the best option for both the Cartier Tank Must and Tank Solo. One example is a custom baby blue lizard strap, which creates a striking contrast with the classic Cartier dial. The fine scale texture of lizard leather adds visual interest while still maintaining the refined elegance that suits the Tank so well.
Beyond aesthetics, the biggest advantage of a custom strap lies in how it is constructed. Because the strap is made specifically for the watch, the leather at the lug area can be thinned slightly so that it slides comfortably between the Tank’s short lugs without creating pressure or distortion. This allows the strap to sit naturally against the case and preserves the clean, architectural lines that define the design.
Custom sizing also solves the issue of unconventional lug widths such as 17.5mm or 22.5mm on the Tank Solo. Instead of forcing a standard strap to fit, the leather can be cut precisely to the correct width, ensuring a secure and seamless fit.
On top of that, custom straps allow you to tailor the finer details such as stitching colour, taper, padding, and lining. These small choices give you the freedom to create a strap that feels uniquely yours while still complementing the timeless design of the Cartier Tank.
Made-to-order straps
For those who prefer something simpler and faster, our made-to-order (MTO) straps are a great middle ground. MTO straps are produced much quicker than a fully custom strap, typically taking around two weeks compared to four weeks for a fully bespoke build. They are ideal if you are looking for a clean, straightforward leather strap without extensive customization. You simply choose the leather type, colour, preset S/M/L length, and whether you would like padding. The result is a strap that still fits the watch properly while keeping the process quick and straightforward. In the examples shown here, ostrich leg straps in gold and olive offer two very different looks, one warm and classic, the other earthy and understated, while showcasing the distinctive scaled texture that makes ostrich leg leather so unique.
Final thoughts
The Cartier Tank is one of the most elegant watch designs ever created, but its distinctive case construction makes strap selection slightly more nuanced than many owners expect.
While regular leather or rubber straps may fit the Tank Must or Tank Solo, the short lugs and unusual lug widths mean the results can vary. For the best fit and cleanest integration with the case, a custom strap with thinner leather at the lugs is often the ideal solution.
Whether you choose a Slim Horween Chromexcel leather strap in burgundy or olive, a vibrant TrimFIT Mosaic strap in yellow or turquoise, or a fully custom baby blue lizard strap, the right strap can transform the personality of the watch while preserving its timeless elegance.
With the correct proportions and thoughtful material choice, the Cartier Tank continues to prove why its design has endured for more than a century.
