I recently went to a tack store to try western saddles.
In Aussies I ride 16.5 to 17, about the same for English, so by taking off 2 inches I “should” ride a 14.5 to 15. I’m lucky to pass the 5’ 1” mark on a fluffy hair day, but am athletically built.
So, I walked in the store and the crusty old owner asked what she could help me with and when I told her I was looking for a size 15 western she nearly busted out laughing.
She really was crusty (having been a tack store owner since... goodness Ii could only guess a long long time!) but also very kind and explained that there is so much more to saddle/rider fit than a number.
Obviously leg length is one, but also hip spread vs. the twist of the saddle, thigh size, and of course the room between the pommel and cantle. This was an important factor as just because the saddle is stamped 15 doesn’t mean the space between the outer pommel area and cantle edge are all the same.
She had me sit in a variety of 15s. A few were tight but rideable, but most didn’t fit at all so we moved up to 15.5 and 16s.
And depending on all the above mentioned factors some of the 15.5s were ok and only some of the 16s were ok.
Then she put me in the men’s saddles (the ones that the men always gravitate to) to get a feel for the difference in the twist and how it affected my comfort. Because of my shorter thighs, a narrow twist felt better for me and would give me the impression of having closer contact without feeling pulled apart.
To say I was educated that day is an understatement.
I'm 5' 1''
English- 16 to 17
Aussie- 16.5 to 17
Western- 15.5 to 16
Weight withheld for a reason.