Thank you for your question and sorry for the late response! To be honest I don't have a specific way of calculating SL, as I usually put the SL at a level high enough, where I am almost sure if it breaks through it I am no longer interested in that trade, no matter if I see the price changes its direction back towards my target. With two words, Broken SL = forgetting about the trade, also I am giving it about 10 to 20 ticks more of what I initially had in mind as a SL, it saved me so many times :). I follow this principles about SL and am very happy with it. I hope this answers your question.