Saddle sizing??

[Mbronze]

I am about to sell one of my saddles on Ebay, I haven't used it for two years as horse that used to wear it has since retired. I think it is a 17 1/2 MW but am not exactly sure.
Is there anyway I can measure it to make sure of the correct size?

 

[Toby_Zaphod]

Normally you measure from the stud at the front of the saddle (at the side of the withers) to the centre of the cantle. That gives you saddle length. As for width, many measure across the gullet between the D rings.

 

[Mbronze]

Thank you