Frequently Asked Questions

Frequently Asked Questions

What is WatchSize.io?

WatchSize.io is a free watch comparison tool that lets you compare any two watches side-by-side at true physical scale. Every watch image is calibrated to its actual lug-to-lug measurement so proportions on screen accurately reflect real-world proportions. The site also includes a wrist try-on simulator, full specifications for every watch, and detailed comparison pages.

How do I compare two watches?

Go to the homepage and use the watch selectors to choose two watches. You can search by brand or model name. Once both watches are selected, they appear side-by-side at true scale. Toggle between side-by-side and overlay views, and scroll down to see a full specs comparison table. You can also visit any pre-built comparison page from our catalog for detailed analysis.

What does true scale mean?

True scale means every watch image on the site is sized proportionally to its real-world dimensions. If a Rolex Submariner has a 48mm lug-to-lug distance and a GMT-Master II has a 47.4mm lug-to-lug distance, their images on screen will reflect that exact size ratio. This makes visual comparisons meaningful — you can see the actual size difference, not just read about it in a spec sheet.

What is lug-to-lug distance and why does it matter?

Lug-to-lug distance is the length from the tip of one lug to the tip of the opposite lug. It is the most important measurement for wrist fit because it determines whether a watch physically fits your wrist. If the lug-to-lug distance exceeds the flat width of your wrist, the lugs will overhang the edges and the watch will look oversized. Two watches with the same case diameter can have very different lug-to-lug measurements, which is why WatchSize.io highlights this spec prominently.

How does the wrist try-on simulator work?

The wrist simulator lets you enter your flat wrist width (measured across the top of your wrist) and select any watch from our catalog. It then renders the watch on a wrist diagram at true proportions, with color-coded fit zones showing whether the watch fits within your wrist (green), extends slightly (yellow), or significantly overhangs (red). It is designed to help you judge fit before buying.

How accurate are the measurements?

All specifications are sourced from official manufacturer data and cross-referenced against multiple published sources. Watch images are scaled using each model's lug-to-lug measurement to ensure proportional accuracy. While we strive for accuracy, manufacturer specifications can vary slightly between production runs, and actual measurements may differ by small margins from published specs.

How do I measure my wrist?

For the wrist simulator, measure the flat width across the top of your wrist just below the wrist bone. Place a ruler perpendicular to your arm and note the distance from one side to the other in millimeters. This flat-top measurement corresponds to the maximum lug-to-lug distance your wrist can accommodate. For more detail, see our watch sizing guide.

What brands and watches are available?

WatchSize.io currently includes over 120 watches across 30+ luxury brands including Rolex, Omega, Cartier, Patek Philippe, Audemars Piguet, Tudor, IWC, Grand Seiko, TAG Heuer, Breitling, and many more. We regularly add new models. If a watch you want is missing, you can submit a request.

How do I request a new watch?

Visit the Request a Watch page and submit the brand and model name of the watch you would like added. We review requests regularly and prioritize popular models. Adding a new watch requires sourcing accurate specifications and a suitable transparent product image, so it may take some time.

Is WatchSize.io affiliated with any watch brands?

No. WatchSize.io is an independent tool built for watch enthusiasts. It is not affiliated with, endorsed by, or sponsored by any watch manufacturer, brand, or authorized retailer. All trademarks and brand names are the property of their respective owners and are used for identification purposes only.

Is WatchSize.io free to use?

Yes. WatchSize.io is completely free. The comparison tool, wrist simulator, and all watch specifications are available without registration or payment.