Mana calculator:
http://www.geocities.co.jp/Playtown-.../manacalc.html
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CALCULATIONS: (for ease of reading I only added WI to the equation but the INT calculations should be the same.)
Below 200 WI/INT:
Mana = ( [ 850 * level ] + [ 85 * WI * level ] ) / 425
This can be simplified to: (WI+10)*level/5
Above 200 WI/INT:
Mana = ( [ 11250 * level ] + [ 33 * WI * level ] ) / 425
As far as being exactly at 200, I'm not sure if it falls in the below or above category. I've heard conflicting things.