(EDITED for clarity)
This tool will show you how many kills it takes a any race/class combination to solo to 50:
http://www.bardsguild.com/everquest/eqexp.html
You can edit it by changing the level disparity between you and the mobs you are fighting as well.
Then of course you can do averages. If you are fighting mobs that are roughly 50/50 split between 1 level below you and 2 levels below you then you can just do an average of the 2 results.
If a solo player finds that their exp is not matching these results then we currently do not have classic exp in place.