There is bound to be an optimal height for an anvil relative to the user.

This will be for "occasional medium duty use, not heavy daily forging.

I am getting to cut my log base and would like some suggestions for the anvils work surface compared to my body.
Bound to be easier working and less tiring when it is "correct".
How sucessfull would I be using a piece of 8" I beam with appropiate base instead of a log

Stand next to your anvil with your shoulders squared and your arms straight down and fist closed. Your fist should rest on the top of your anvil. I have 2 at that height and my straightening/tuning anvil set higher than that.

Thank you!

Jerry beat me to it, TC. Do you have a copy of Lorelei Sims' book? I have found it very helpful, but I am a rank amateur.