Just thought I would bring this up since so many people don't have a clue... You should be able to get a finger or two in the girth. It shouldn't be easy, but you shouldn't have to struggle for two minutes trying. To be even more clear, you should be able to wiggle the girth a little so the skin moves with it. If you can't, or you have to apply a lot of effort, you have a problem. The girth should not be indenting into your horse's side! I've seen so many people tighten it until they can't possibly make it any tighter. The horse does not appreciate that!!! Girth fit also depends on what you are doing. If you plan to go run a barrel pattern at top speed, do a meter jump off, do some pony games or trick riding, you will want a tight girth so you don't come off! However, the second you're done with the barrels, the jump round, games, or circle of tricks, the girth should be immediately loosened. For me, if I'm just trail riding, I ride with a looser girth. If I'm riding a new horse or a horse that is known to buck/rear/kick, I'll ride with a tighter one. Also, if the girth has lots of elastic, I also ride with a tighter girth especially if it's one that has a tendency to slip, a drawback with girths that have lots of elastic. (Not barrel/jump off/trick riding/pony games tight though!) You want to aim for something snug that won't slip but won't have your horse struggling to breathe. I'm assuming you all know this, but in case you didn't, I hope this helps! 😁