Tissot Seastar 1000 Chronograph 45.5 mm on the wrist: size, weight and who it suits
Updated 4 November 2026. By Carlos Iglesias, ArTempo, Maastricht.
The Seastar 1000 Chronograph is the biggest watch we stock. 45.5 mm is a number that puts some people off before they have seen it on a wrist, so here are the measurements, what they mean in practice and a simple test you can do at home.
The numbers
| Seastar 1000 Chronograph | PRX 40 mm quartz | |
|---|---|---|
| Reference | T120.417.11.091.01 | T137.410.11.041.00 (blue) |
| Case diameter | 45.5 mm | 40.0 mm |
| Thickness | 12.82 mm | 10.40 mm |
| Lug width | 22 mm | Integrated bracelet |
| Weight | 180 g | 130 g |
| Water resistance | 300 m (30 bar) | 100 m (10 bar) |
| Crystal | Sapphire | Sapphire |
| Movement | Swiss quartz chronograph | Swiss quartz |
| Tissot RRP (Netherlands) | €645 | €395 |
RRP from tissotwatches.com (NL), checked 25 October 2026. Weights are for the watch on its full steel bracelet.
What 45.5 mm and 180 g mean on the wrist
The Seastar is 5.5 mm wider than the PRX 40, 2.4 mm thicker and 50 g heavier. You notice the weight when you first put it on and stop noticing it after a day or two, which is the usual experience with a steel diver-style chronograph. The 22 mm lug width also means you can swap the bracelet for a rubber or fabric strap, which makes it lighter and a little more casual.
Who it suits
- Wrists from about 17.5 cm up: it looks in proportion.
- Wrists of 16 to 17.5 cm: it works if you like a watch with presence. Try the paper test below first.
- Wrists under 16 cm: it will look large. The PRX 40, or a 35 mm PRX on request, is the better choice.
It is also the watch for people who swim, sail or simply do not want to think about water: 300 m is far more than daily life asks for.
The five-minute paper test
- Draw a circle 45.5 mm across on paper (a compass set to 22.75 mm, or trace round something that size and check it with a ruler).
- Cut it out and lay it on your wrist where you wear a watch.
- Look in a mirror from arm's length. If the paper reaches beyond the edges of the top of your wrist, the watch will look large on you.
Check it is genuine
Every Seastar we sell is new, in its original Tissot box, and the reference T120.417.11.091.01 and EAN 7611608298374 on the box can be checked against Tissot's own catalogue. Our guide How to check that a Tissot is genuine shows how.
Availability
We stock it with the green dial in small numbers: its product page shows whether it is available. If it has sold, join the drop list and you will hear about the next one 24 hours before it goes on sale.