I found this baby

http://mywebpages.comcast.net/proc/civ4/combat_calc.htm

I'm glad you've found it. I've found it really useful in balancing the handful of UBs I've made for myself.

Very nice.
But you must take care with promotions, they're not inclusive. I noticed that different results are given for example wof unit with a) City Raider II and b) City Raider I + II.
So remember to check ALL promos, not just the highest ones :)

Sweet you need to ask if you can incorporate this with civfanatics.