How do you work out what size girth you need?

Well, i don't know if the correct way but i have always put a saddle on my horse and got a friend to hold a weigh tape on approx the 2nd or 3rd hole of the girth straps and i put the other end on the straps on the other side and that gives you in inches the girth length.
Always worked for me but i don't have the elastic girths ends so if you have them you might need to get a size smaller?
Otherwise ask around your yard and try other peoples on for size?
 
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