For most people, yes. A 39 mm watch suits most wrists from about 15 cm upwards, but the number that decides fit is lug-to-lug length: if the lugs stay on the flat top of your wrist, the watch fits. KOMPAS, our own watch, is 39 mm across with a 46.5 mm lug-to-lug and is 10.4 mm thick.
Buying a watch online always comes with one nagging question: will it fit? A watch that looks perfect in photos can overhang a slim wrist or look lost on a large one. 39 mm is one of the most versatile sizes there is, right at the upper end of the classic field watch range, but diameter is only part of the story. This guide shows you how to measure your wrist, which numbers actually decide fit, and how a 39 mm watch like KOMPAS is likely to wear on you.
The four numbers that decide fit
Every watch has four measurements that matter on the wrist. Here they are for KOMPAS:
| Measurement | KOMPAS | What it tells you |
|---|---|---|
| Case diameter | 39 mm | How wide the watch looks from the front, not counting the crown |
| Lug to lug | 46.5 mm | How much of your wrist the watch covers, top to bottom. The most important number for fit |
| Thickness | 10.4 mm | How high it sits, and whether it slides under a shirt cuff |
| Lug width | 20 mm | The strap width. Affects proportions and strap choice |
Why lug-to-lug matters more than diameter
Diameter gets the headlines, but lug-to-lug is what decides whether a watch fits. It is the distance from the tip of the top lugs to the tip of the bottom lugs, and it tells you how much of your wrist the watch spans.
The rule is simple: the lugs should not extend past the flat top of your wrist. If they overhang the edges, the watch looks too big and the strap can't wrap neatly. A 39 mm watch with short lugs can wear smaller than a 38 mm watch with long ones.
At 46.5 mm, KOMPAS has a compact lug-to-lug for a 39 mm watch. For comparison, the Hamilton Khaki Field Mechanical 38 measures 47 mm. Our comparison of the best field watches under £600 lists the lug-to-lug of every watch in it.
Thickness and the shirt cuff
At 10.4 mm, KOMPAS is slim enough to sit comfortably under most shirt cuffs while still housing an automatic movement and a display caseback. At this height, most people soon stop noticing the watch is there.
Lug width and proportions
A 20 mm lug width is a classic proportion for a 39 mm case: about half the diameter. It also means a huge choice of straps. KOMPAS comes with two quick-release straps, rubber and nylon, so you can change them in seconds without tools.
How to measure your wrist
You need two measurements: the circumference of your wrist and the width of its flat top.
Circumference: three ways
- Flexible tape measure. Wrap it around your wrist just above the wrist bone, where a watch sits. Keep it snug but not tight, and read the number in centimetres.
- String or paper strip. No tape? Wrap a strip of paper or a piece of string around the same spot, mark where it overlaps, then lay it flat against a ruler.
- An existing strap. If you already own a watch that fits well, measure the strap from the hole you use, around to the buckle.
Flat-top width
Look at your wrist from above. Most wrists are oval, with a flatter top. Hold a ruler across the top of your wrist, where the watch sits, and measure the width of the flat part, from edge to edge before it curves away. This is the number to compare with the 46.5 mm lug-to-lug.
Two people with the same circumference can have different flat-top widths. A flat, wide wrist can carry a longer lug-to-lug than a round one.
The paper template test
For the best preview, cut out a paper rectangle 46.5 mm long and 39 mm wide. Lay it on your wrist, long side running along your arm. If the ends stay on the flat top of your wrist, KOMPAS will fit. Look in a mirror, and at a photo of yourself from a normal distance; that is how others will see it.
39 mm wrist size chart
Use this as a starting point. Wrist shape matters too, so the paper test is always worth doing.
| Wrist circumference | In inches | How a 39 mm KOMPAS is likely to wear |
|---|---|---|
| Under 15 cm | Under 5.9 in | On the bold side. Check the 46.5 mm lug-to-lug against your flat-top width. Many slim wrists still wear it well because the lugs are short |
| 15–16 cm | 5.9–6.3 in | Full but balanced, especially on a flatter wrist. A nylon strap sits flatter and helps it hug the wrist |
| 16–17.5 cm | 6.3–6.9 in | The sweet spot. Classic field watch proportions with room to spare |
| 17.5–19 cm | 6.9–7.5 in | Classic and understated. Looks the way a traditional field watch should |
| 19–20.5 cm | 7.5–8.1 in | Wears modestly, with a vintage feel. Ideal if you prefer a watch that doesn't shout |
| Over 20.5 cm | Over 8.1 in | Compact on the wrist. Some people at this size prefer 40 mm and up; many like the understated look. Check strap length before ordering |
Why 39 mm works for so many people
Field watches have always been modest in size (our guide what is a field watch? explains why), and today most sit between 36 and 40 mm. 39 mm sits right at the upper end of that classic range: large enough to read the dial at a glance, small enough to forget you are wearing it.
It is also a size that suits different settings. On a rubber strap it looks at home on a hike or at the pool; on nylon it works with jeans and a jacket; under a shirt cuff it doesn't get in the way. That versatility is why 39 mm has become one of the most popular sizes for an everyday watch.
On a KOMPAS, the dial also helps. The 12 layered triangular segments, inspired by the RAF sector clock, run right around the dial and make it read clearly from edge to edge. Read how to read a 5-minute dial for more.
Factors beyond the numbers
Strap choice changes the look
A rubber strap gives a sportier, slightly more substantial look. A nylon strap sits flatter and can make the watch feel lighter on the wrist. Since both come in the box, you can try each.
Dial colour changes perceived size
Darker dials, like North in black, tend to look slightly more compact. Brighter or lighter colours can look a touch larger. South in blue sits between the two.
Wrist shape matters as much as size
A flat wrist can carry more watch than a round one of the same circumference. That is why the flat-top measurement and the paper test are more reliable than circumference alone.
Personal taste
Some people like a watch that fills the wrist; others prefer one that sits neatly within it. There is no wrong answer, only what you enjoy wearing.
Still unsure? Try it at home
Ordering from the KOMPAS online store comes with free tracked shipping to more than 40 countries and 14-day returns, so you can see the watch on your own wrist before you decide. Every KOMPAS is £535 and covered by a 2-year international warranty.
If your wrist is at either end of the chart and you are not sure about strap length, get in touch before you order and we'll help.
North (black) and South (blue) are in stock at the time of writing; East (green) and West (red) are sold out, with a waitlist on the watches page. Every dimension is on the technical page.
Frequently asked questions
Is a 39mm watch too big for a small wrist?
Not usually. A 39 mm watch suits most wrists from about 15 cm upwards. What matters most is lug-to-lug length: KOMPAS measures 46.5 mm, so check that this fits within the flat top of your wrist.
Is a 39mm watch too small for a large wrist?
Not necessarily. On wrists over about 19 cm, a 39 mm watch wears modestly and has a classic, vintage feel. Many people prefer that; others prefer 40 mm and up. It comes down to taste.
How do I measure my wrist for a watch?
Wrap a flexible tape, string or paper strip around your wrist just above the wrist bone, snug but not tight. Then measure the width of the flat top of your wrist with a ruler and compare it with the watch's lug-to-lug length.
What does lug to lug mean?
It is the distance from the tip of the top lugs to the tip of the bottom lugs. It tells you how much of your wrist the watch covers. For a good fit, the lugs should not overhang the flat top of your wrist.
What strap size does KOMPAS use?
KOMPAS has a 20 mm lug width. It comes with two quick-release straps, rubber and nylon, and fits any standard 20 mm strap.
Is 10.4 mm thick for a watch?
No. 10.4 mm is slim for an automatic watch with a sapphire crystal and exhibition caseback, and it fits comfortably under most shirt cuffs.
