I know that the answer to this question will have many variables, but I would like an average if possible.
Say a bow pulls 50# at 28".
How many pounds will you loose for each inch taken off the draw length?
For example, about what will the draw weight be if a child with a 20" draw length uses it?
"rule" is 3#/inch if the bow is performing obiently....
There are lots of draw down charts in my reviews that should give you an idea what to expect from brace to 28". click the trad review pages at www.peteward.com (http://www.peteward.com)
Grab the bow scale and give it a pull to your draw. You will know for sure, no guessing on what you are pulling.
There is a more precise rule than BobW's but it is still an approximation. Take the drawweight at the rated draw length, deduct the inches of brace height and divide the remaining inches into the weight.Ex>60@28 minus 8 inch brace=20 inches-60 divided by 20 =3lbs ber inch(BobW's answer). Do it with a 40lber and you would get 2 lb per inch 50 lber=2.5lbs etc. This gets you close but since force/draw curves are CURVES rather than straight linear progressions it may be slightly off.