Leathergoods Business

A business question for the group. What would you say is the yield on a veg tan side? I'm pricing a basic job out for someone and I don't want to undercut how much leather I'll need. I know each piece of leather I need is about 8x5 or so on some eye glass sleeves and want to buy hides as they are much more economical.

So for instance if I buy a 22ft hide is it safe to say may 10% is unusable for the project based on scars and marks or possibly more? I know so many say the main item you need to calculate right for is your leather or you can kiss your profit away haha.

Thanks all,

Matt