i know this is an old post but i figured i throw this in there, this is what they're teaching in marine corps sniper school for calculating windage adjustments as of 2013:

range (yards) x wind 1 + wind 2 + constant

range is simple- 100 yards is .1, 200 yards is .2, after 500 though, add .1, so 500 is .5, but 600 is .7 and 700 is .8 etc..

wind 1 is wind speed in multiples of 5 - 0-4mph is 0, 5-9=1, 10-14=2 and so on.. so round down to nearest multiple of 5 then 0=0, 5=1, 10=2, 15=3 etc..

wind 2 is wind NOT in multiples of 5, but whatever your multiple of 5 was from wind 1 plus .1 for every one more so: if wind speed is 6 then- wind 1=5 which 5=1, plus the .1 because 6 is one more than 5, so wind 2 would be .1, or if my wind speed was 13, it would be .3, or if it was 9, it would be .4

then the constant- the constant doesnt start until 400 yards, 400 =.1, 500=.2 and so on

so lets put it together, if i had a target at 700 yards with a wind speed of 19 mph (full value) then my equation would be: range x wind1 + wind2 +constant , so .8 x 3 +.4 +.4= 3.2 mils for my windage adjustment or if i had a target at 400 yards with 6mph winds at HALF value then it would be 400 yards with 3mph so- .4 x 0 + .3 + .1= .4 mil windage adjustment

i apologize if i wrote this out horribly, if its too difficult, let me know and i can provide a picture from my data book to explain it WAY easier.

also to elaborate on helping people understand what a mil is, think of mils like you do moa, 1 mil = 3.6 inches , 1 MOA is 1.047 inches @ 100 yards, so -- 1 mil = 3.438 MOA or 1 MOA is .29 mils

also not to confuse people but some marine corps mil-dot sights are completely different, im not going to elaborate because its too hard to explain without a picture but they make the spaces between the dots .6 mils and the dots .2 mils so its more accurate, so half dot is .1, a dot the space and another dot = 1 and so on, its just a way to make it more precise

again, sorry if i made it too complicated, let me know if anybody wants me to try to explain it a little better.