Custom watch strap length: Too little, too much, just right?
If all you want is to know what size strap to order, go to my FAQ here, the practical details are explained in the first section, "Strap lengths and widths explained" and there's a chart for length based on wrist size.
When it comes to strap length with handmade leather watch bands, a few things are written in stone (don't guess, too short is never good, not all straps fit the same) and the rest is a matter of taste. When you're ordering your own Panerai strap (or Rolex or any brand) how do you know what length is the right length, and more importantly... why is one length "right" and another "wrong"? You're about to find out.
Longer is better, except when it's not
I happen to prefer longer custom watch bands, meaning: A good amount of tongue sticking out so you can use both keepers and have some style, and with the buckle off to one side in the first or second hole down from the lugs of the watch so it's not in the center softest part of the wrist. This is a casual look that's well suited to the aftermarket watch straps I make by hand. If you're seeking for a more formal look, a shorter strap would be better, aka not too much tail and with the buckle centered. This is generally suitable for leather watch bands being used on smaller non-Panerai watches.
Just a smidge of tail sticking out on my Blueberry Horween
How long is my thick strap going to be, or how I learned that length isn't always about length
One of the major factors when ordering a custom, handmade leather watch strap is thickness. The thickness of a watch band has a huge effect on how long that strap "wears" on the wrist. For instance: If you have two straps that are both 130/80 length laid out flat on a table but one is 4mm thick while the other is 3mm thick, they will fit very differently on your wrist. The rule of thumb is: thicker custom watch straps wear shorter. In layman's terms, if you have a strap that's 3mm thick and it fits you perfectly at 130/80, one of my 4mm thick straps in that same length will fit you a little short.
Perfect buckle placement
Panerai vs. the world
Another complicating factor in strap length is: What watch is the strap for? Larger watches (42mm and up), such as Panerai and many Bell and Ross watches, are much better suited for longer straps as they are already a more casual looking watch, usually with a military history that supports the longer style of custom watch strap. Panerai in particular used very long straps (160/120 etc) due to the watches originally being worn over bulky drysuits for diving, leading to a modern preference by collectors for longer straps with lots of tail and an off-set buckle. Smaller watches such as Rolex, IWC, JLC etc. tend to look better on shorter straps as they are generally more modern looking watches that are used in more refined settings.
Yeah but what's right for ME?
That all depends on your wrist size, what watch the strap is for and what you prefer... longer, shorter, historic, modern etc. Only you can answer those questions, and then usually only by trying different length straps. Most Panerai people get longer and longer straps until they reach a practical maximum, and then settle on a place about 2/3rds of that maximum length. This provides a nice historic look in line with the history Panerai has of using very long straps without being overly bulky or uncomfortable. For instance, on my own 7.75" wrist I generally prefer a 145/95 length. On non-Panerai watches people generally like a custom leather watch band with a more refined look with less tail and a more centered buckle.