If you use the calculator link Paulosantos provided you can type in scope height, wind factors, etc etc etc. Even temperature, humidity, the whole shooting match. You can even click on many of the bullets you'd be using, like the Sieraa 110 gr Prohunter. It automatically figures in the ballistic co-efficient and all that great stuff. You're just several mouse clicks away from being a ballistician. Then, using your setup, you can make the best decision on what to use for a sight-in range. Should I be 1.5" high at 100 yards? Hmmmm. Probably not if you can't only shoot 50 yards where you hunt. Probably so if occasionally 200 shots present themselves. Oh, what a plethora of decisions to make.
So, the website gives you the best answer possible. All PEOPLE can give you is their best guess for their experience. So, if someone gives you a good sight in range, and then you find out later that they bench rest sight their guns in at 7,200 ft elevation, you may have received good intentions but skewed date if you hunt at sea level. By the way, the link mentioned above can be altitude adjusted and is as simple as 1,2,3 to input the data. By the way, when sighting in for my .270, .300 H&H, 7mm-08, etc, the program has been reaalllll close.