# How exactly "case size" measurement is determined?



## aceproceed (Sep 4, 2007)

Hello, I'm curious about this and have searched but not found any threads on the subject.

On many of the sites when describing the watch it will say for example case size - 43mm wide x 13 mm thick.

Others will say "dial size" "case diameter" etc.

Is the way in which they measure different for every watch and whoever is selling it?

In general, when they're describing the case size, is it the entire width from side to side including the knob for setting the time? Or is it the diameter of the dial itself? Bezel included or not?

It seems confusing and difficult to determine exactly what the measurement refers to precisely.

Thank you.


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## Guest (Oct 14, 2007)

Not confusing or difficult to me. In my understanding (and experience) it´s always the diameter of the case incl. bezel excl. crown.
The dial diameter doesn´t play a role because it is always smaller. The lugs don´t play a role too.


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## Tragic (Feb 11, 2006)

Well Mike the lugs play a role length wise.
On a large watch it's wise to know the lug to lug length.
It's silly looking I think when a watch overhangs one's wrist.


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## Guest (Oct 14, 2007)

Tragic said:


> Well Mike the lugs play a role length wise.
> On a large watch it's wise to know the lug to lug length.
> It's silly looking I think when a watch overhangs one's wrist.


I know, but the lug to lug length isn´t the diameter.;-)


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## Chascomm (Feb 13, 2006)

I've noticed that not many people worry about case _area_, particularly with regard to tank, tonneau and cushion cases. I recall one discussion in which somebody, on hearing that the Vostok Attache was less than 40mm wide concluded that it was too small for his manly wrist :-d He didn't stop to consider the surface area of a rectangle in comparison to a circle of the same width.


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## SnapIT (Apr 29, 2005)

I've been under the impression that measuring on the 8-2 diagonal gives the "truest" measure of outside dimension of the case when considering round face watches. That coupled with the lug to lug dimension gives a good XY ratio.


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## boneycat (Dec 27, 2007)

I thought I'd revive this thread because I have this same question and am still unclear as to how to measure a watch. Let's say I take a diving watch where the case juts out a bit at the 9 o'clock position as well as where the crown inserts to. Do I measure from the widest part of the case (9 o'clock) to the opposite side?


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## Guest (Feb 17, 2008)

boneycat said:


> I thought I'd revive this thread because I have this same question and am still unclear as to how to measure a watch. Let's say I take a diving watch where the case juts out a bit at the 9 o'clock position as well as where the crown inserts to. Do I measure from the widest part of the case (9 o'clock) to the opposite side?


I´d do so. Don´t know what the manufacturer did :-(


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## mjbernier (Sep 30, 2007)

I'm no expert, just passing along what I've seen and read in a few places...the most common method I've read in determining the basic case size is to measure on the outside of the case with calipers along a diagonal from the 8 o'clock to 2 o'clock position, or from the 10 o'clock to 4 o'clock position -- the specific position you choose is determined by where the crown is located...you don't want to include the crown in the measurement. Some people do take a second measurement including the crown as well, and I've seen it quoted as "case diameter including crown", which I suppose is useful if you need to know the absolute maximum width of the watch as it sits on your wrist. I'm not sure how they work out the measurements if it's a chronograph with pushers - perhaps they alter the diagonal a little bit to miss them...point being, the case measurement is supposedly what the diameter of the case would be if nothing was sticking out of it.

Case thickness seems to be similarly confusing - supposedly, you measure with a caliper from the highest point on the front of the watch to the highest point on the caseback, but again there are variations I've seen, depending on whether the bezel ring is higher than the crystal (as on some dive watches), or other measurements like "crystal thickness" which seem a little dubious.

I agree on the lug length comment - it's important to understand that measurement, especially if you have a smaller wrist and don't want something sticking out. 

Hope this helps...
Mike


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## CuriousG (Jan 25, 2008)

mjbernier said:


> I'm no expert, just passing along what I've seen and read in a few places...the most common method I've read in determining the basic case size is to measure on the outside of the case with calipers along a diagonal from the 8 o'clock to 2 o'clock position, or from the 10 o'clock to 4 o'clock position -- the specific position you choose is determined by where the crown is located...you don't want to include the crown in the measurement. Some people do take a second measurement including the crown as well, and I've seen it quoted as "case diameter including crown", which I suppose is useful if you need to know the absolute maximum width of the watch as it sits on your wrist. I'm not sure how they work out the measurements if it's a chronograph with pushers - perhaps they alter the diagonal a little bit to miss them...point being, the case measurement is supposedly what the diameter of the case would be if nothing was sticking out of it.
> 
> Case thickness seems to be similarly confusing - supposedly, you measure with a caliper from the highest point on the front of the watch to the highest point on the caseback, but again there are variations I've seen, depending on whether the bezel ring is higher than the crystal (as on some dive watches), or other measurements like "crystal thickness" which seem a little dubious.
> 
> ...


Nice post. I think you got at what the OP was trying to find out about. You caught all the pertinent details.


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## boneycat (Dec 27, 2007)

Agreed, very helpful post Mike. I salute you sir .


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## mjbernier (Sep 30, 2007)

Thanks for the kudos - it's nice to know I can contribute something actually useful out here every now and then!

Mike


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## hiro1963 (Feb 4, 2008)

Here are some examples...

Omega Planet Ocean 42

Advertised Size: 42

Width: 2:00 - 8:00: 42.7

Omega Seamaster Professional full size

Advertised Size: 41

Width: 2:00 - 8:00: 41.2

FYI,

Bezel Diameter

42 PO: 39.8
SMP: 40.8

Because of that, the SMP looks bigger than the 42 PO on your wrist. So, sometime the case size is not a deciding factor. You have to try it on.


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## Edo123 (Sep 9, 2013)

I've just found a watch online which has a 40mm 'case diameter'. I really like the watch but 40mm is slightly big for my wrist. I'd be more happy with a 38mm but good watches rarely come in that size :-(. My question is does the 40mm include the crown or is is it just the measurement if the dial? (The crown is by no means small on that watch so I'll be really lucky if its included within the 40mm lol.


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## StufflerMike (Mar 23, 2010)

Usually it is without crown.


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