on my scope it says 1click 1 cm at 100 meters. lm zeroed in at 200 meters and the bullet dropes about 80 cm at 400 meters (175 gr 7mm rem mag) how many clicks do l go up?
Easy answer is 20 clicks. At 100, your scope adjusts for the labeled amount. Moving out to 200, it will move twice that, 300, 3 times that, 400, 4times that, 500, 5 times that, etc.
Divide by the factor to determine your clicks. As long as the drop is in the same calibration as your scope, you'll be close. A ballistics program will allow you to change from cms to clicks as a cross check.