What watch size for my wrist? The chart from 14 to 20 cm
Put two Seiko watches side by side. The first measures 42.5 mm across, the second 39.4 mm. Which one takes up more room on a slim wrist? On paper, the smaller one. On the wrist, it is the other way round: from one lug tip to the other, the "small" watch measures 48.1 mm, against 46 mm for the big one. Yet they share the same movement, the 4R36 calibre. The whole difference lies in the design of the case.
The short answer: measure your wrist, then allow roughly 36 to 39 mm in diameter for a 15 to 16 cm wrist, 38 to 41 mm for 17 cm, 39 to 42 mm for 18 cm and 40 to 44 mm above 19 cm. But diameter is not enough: the lug-to-lug length should never exceed the width of the top of your wrist. Here is how to measure in two minutes, the full chart from 14 to 20 cm, and the details that make a watch look bigger or smaller than it really is.
Measure your wrist in two minutes
No need to visit a jeweller. Three methods will do, and the first is the most reliable.
- A sewing tape measure. Wrap it just above the wrist bone, where a watch sits, without pulling tight. Read the measurement to the nearest millimetre.
- A strip of paper. Cut a strip of paper one centimetre wide, wrap it round your wrist, mark with a pencil where it meets, then measure it flat with a ruler.
- The watch you already wear. Measure the closed bracelet, from the inside of the clasp to the case, then add the length of the case. If it fits you well, you have your measurement.
Measure at the end of the day: the wrist swells slightly with heat and activity. And note a second figure that people often forget: the width of the top of the wrist, seen from above. Lay a ruler flat on your wrist and measure from one edge of the flat part to the other, where the skin starts to slope down at the sides. That figure decides whether a watch "overhangs".
The chart: which diameter for a 14 to 20 cm wrist
These are the guidelines we use in the workshop when a customer is unsure. They are not laws: a very thin watch can get away with two extra millimetres, a thick one with two fewer. The last column gives the lug-to-lug length not to exceed if you want the case to sit well.
| Wrist size | Recommended diameter | Maximum lug-to-lug | Our advice |
|---|---|---|---|
| 14 cm | 34 to 36 mm | 42 mm | Round, thin case, understated dial |
| 15 cm | 35 to 38 mm | 44 mm | A 36 mm fits just right |
| 16 cm | 36 to 39 mm | 46 mm | 36 mm discreet, 39 mm noticeable |
| 17 cm | 38 to 41 mm | 48 mm | The easiest wrist to dress |
| 18 cm | 39 to 42 mm | 50 mm | A chronograph finds its place |
| 19 cm | 40 to 44 mm | 52 mm | Sports cases come into their own |
| 20 cm | 42 to 46 mm | 54 mm | Avoid very thin cases, they would look lost |
If you fall between two rows, think about your style rather than the rule. For a watch worn with a shirt, take the lower end of the range: it should slide under the cuff. For a sports watch or a chronograph, the upper end works without any problem.
The diameter trap: two Seiko watches that fool everyone
Back to the two watches at the start. Both are Seiko 5 Sports, both powered by the automatic 4R36 calibre, and their official specification pages say it all:
| Measurement | Seiko 5 Sports SRPD55 | Seiko 5 Sports SRPH29 |
|---|---|---|
| Diameter | 42.5 mm | 39.4 mm |
| Lug-to-lug | 46 mm | 48.1 mm |
| Thickness | 13.4 mm | 13.2 mm |
| Lug width | 22 mm | 20 mm |
| Stated weight | 170 g, steel bracelet | 75 g, nylon strap |
The first has a wide case but short, down-turned lugs: it spreads across the wrist and hugs it. The second, a slimmer field watch, has long, straight lugs: it stretches lengthways. On a 16 cm wrist, whose flat part often measures around 5 cm, it is the "smaller" watch that is more likely to overhang.
Remember the lesson: diameter is the figure everyone advertises, lug-to-lug is the one that matters. When a brand does not give it, ask for it, or measure it on a side photo with a ruler placed alongside.
Thickness, weight, colour: what makes a watch look bigger
Two watches with the same diameter can look very different in size once on the wrist. Four details play tricks on the eye.
- The bezel. A wide bezel, graduated or fluted, reduces the dial area: the watch looks smaller. A dial that runs almost to the edge of the case makes it look bigger.
- The dial colour. A light dial (white, silver, ice blue) visually enlarges the watch. A black or burgundy dial tightens it. On a small wrist, a black 39 mm often works better than a white 39 mm.
- Thickness. Beyond 13 mm, a watch shows under a sleeve and tips more easily to the side of the wrist. The two Seiko watches in the table, at 13.2 and 13.4 mm, are average for sporty automatics.
- Weight and strap. A heavy watch on a steel bracelet pulls outwards if the bracelet is not properly sized. The same watch on leather or fabric stays in place and feels lighter. The 170 g of the Seiko on steel and the 75 g of its cousin on nylon give an idea of the gap.
An integrated bracelet, as on octagonal watches, also changes things: it extends the line of the case and makes the whole look wider. On our S Royal, that is the point: the watch is worn like a piece of steel jewellery. On a wrist under 16 cm, try it before deciding, or keep the bracelet one notch tighter.
36 or 39 mm: how to decide
This is the question we are asked most, because three of our families come in both sizes: the Roman Dial with Roman numerals, the watch with a fluted bezel and sunburst dial and the Diams with set indices. Same dial, same automatic movement, three millimetres apart. Here is how to choose.
- Take the 36 mm if your wrist measures under 16 cm, if you mostly wear shirts, or if you like watches that go unnoticed. It is the size of a classic dress watch.
- Take the 39 mm if your wrist is over 17 cm, if you wear the watch every day with a jumper or a T-shirt, or if you want it to be noticed.
- Between 16 and 17 cm, both work. Go by the colour: light dial, stay with 36 mm; dark dial, go for 39 mm.
Three millimetres look like little on a spec sheet. On the wrist, that is about 8% more diameter, and nearly 17% more dial area. The difference shows at first glance.
Slim wrist, large wrist: advice from the workshop
In the workshop, we often see the same hesitation: a slim wrist afraid of wearing "a woman's watch", a large wrist convinced that no classic watch will suit it. Both are wrong.
For a 14 to 16 cm wrist
Look for a round case, short lugs and a bracelet that tapers towards the clasp. Roman numerals and slim indices lighten the dial. Avoid very busy chronographs: three sub-dials on a small dial become hard to read. And have the spare links removed: a bracelet that is too loose lets the watch spin and makes the case look even bigger.
For an 18 to 20 cm wrist
A 36 mm watch is not forbidden, but it needs character: a strong bezel, a coloured dial, a solid steel bracelet. Cases with real presence, such as our Saytona chronograph or the GMT Mod with its two-tone bezel, find their place naturally. Just check the bracelet length: steel bracelets come with a standard number of links, which can be tight beyond 20 cm.
Men's watch, women's watch: a line that has already moved
If the size of a watch seems tied to gender, history suggests otherwise. According to Wikipedia, the first wristwatches were worn almost exclusively by women, while men stayed loyal to the pocket watch until the end of the 19th century. It was British Army officers, in the 1880s, then the soldiers of the First World War who changed the habit: by the end of the war, almost all enlisted men wore a watch on the wrist.
In other words, the "men's watch" as we picture it is a recent invention, and its size has followed fashion. Today, more and more women wear 39 mm cases, and many men are going back to 36 mm. The only rule that holds is the one set by your wrist. To go further on how watches are worn, read why we wear our watch on the left wrist.
Giving a watch without knowing the wrist size
This is the trickiest case: the watch is a surprise, and there is no way to bring out the tape measure. Three tricks work:
- Discreetly borrow a watch or bracelet they often wear, and measure it flat.
- Choose a middle size: 39 mm for most men, 36 mm for a wrist you know is slim.
- Remember that returns are possible within 14 days if the size is not right.
We have gathered the other gift pitfalls in our guide to giving a watch for Christmas, and the criteria for choosing an automatic in giving an automatic watch for under €300.
Frequently asked questions
What watch size for an 18 cm wrist?
For an 18 cm wrist, a diameter of 39 to 42 mm is the most balanced, with a lug-to-lug length of 50 mm at most. A 42 mm chronograph or sports watch fits without overhanging.
What watch size for a 16 cm wrist?
For a 16 cm wrist, aim for 36 to 39 mm in diameter and a lug-to-lug of 46 mm at most. The 36 mm stays discreet under a shirt, the 39 mm stands out more, especially with a light dial.
What is the standard size of a men's watch?
There is no official standard. In practice, most men's watches today measure between 38 and 42 mm. A dress watch often goes down to 36 mm, while a dive watch or a chronograph readily goes above 42 mm.
Is a 40 mm watch too big for a small wrist?
Not necessarily. On a 15 to 16 cm wrist, a 40 mm watch works if its lugs are short, if it stays thin and if its dial is dark. Measure the lug-to-lug: if it exceeds the width of the top of your wrist, the watch will overhang.
How do I measure my wrist without a tape measure?
Wrap a strip of paper or a piece of string round your wrist, mark where it meets with a pencil, then measure the length flat with a ruler. Measure just above the wrist bone, without pulling tight.
Sources
- Seiko, official specification page of the Seiko 5 Sports SRPD55 (diameter, thickness, lug-to-lug, weight, 4R36 calibre): seikowatches.com
- Seiko, official specification page of the Seiko 5 Sports SRPH29 (diameter, thickness, lug-to-lug, weight, 4R36 calibre): seikowatches.com
- Wikipedia, "Watch", history of the wristwatch: en.wikipedia.org/wiki/Watch
- Photos: SmodParis workshop.