How do I calculate the length of the leather strap for a deployant buckle?

[Epimetheus]

I´ve got a Pam177L inbound on which I plan to purchase several different straps for.
I´ve also bought a deployant buckle for one of the leather straps.

My question is how I calculate the correct length of the leather strap.
I have a Pam136K with a bracelet with deployant buckle.
Can I use that bracelet and measure the bracelet on each side of the buckle to get the right length to order the leather strap?

Or should I wait until I have the watch and work from there?

 

[hooligan]

How big is your wrist?

 

[Epimetheus]

How big is your wrist?

8,2" or 21cm.

 

[Epimetheus]

If I use my Pam236K to measure the correct length on the strap, will it fit the 177L then?
Is the 236K and the 177L the same size?
Will the straps be interchangeable between the two watches?

 

[hooligan]

If I use my Pam236K to measure the correct length on the strap, will it fit the 177L then?
Is the 236K and the 177L the same size?
Will the straps be interchangeable between the two watches?

Yes, yes and yes.

For a deployant buckle, it will make the strap wear a little shorter, since the buckle is between your wrist and the strap. FYI.

 

[Epimetheus]

Yes, yes and yes.

For a deployant buckle, it will make the strap wear a little shorter, since the buckle is between your wrist and the strap. FYI.

Thank you so much!
You just made my life a whole lot easier.