These suggestions definitely put you in the ball park, but you'll have to find your own best answer. A clearly specific answer would only apply if all the bows were identical, tillered the same and shot from a machine. How you draw, how you shoot, your form, etc... heck, probably even the arrow, make differences that add up.
If you want to really worry about all of that, it can keep you up all night. I just finished a longbow today - flatbow, actually - and made it a string tonight. I set it up by the old fistmele method and will twist it up and do so again in the morning, to accomodate however much it stretches during the night. That's the way it'll get shot till I get around to paper tuning it with a specific arrow.