alclarkey

I've been all over wikipedia reading about tesla's, webers, gauss, maxwells, oersteds, etc, and I suppose that if I really spent the time, I could have a deep understanding. I was kind of hoping there was a simple equation that could help me. Take the following: http://www.kjmagnetics.com/proddetail.asp?prod=B111 How can I figure out what size magnet of the same material it would take to demagnetize the one I linked?