Can someone help me calculate, I am not good with math :(

[Azilius]

So if you put lvl 64-90 on nivlam SP calc you actually calcualte SP from
[ALTERNATIVE 1]
lvl 64 | 00.00% --- to --- lvl 90 | 00.00%
??

Or is it
[ALTERNATIVE 2]
lvl 64 | 00.00% --- to --- lvl 90 | 99.99%
??

It's the second like gul stated.
Common mistake while calculating too, also as ted pointed out, quests also influence how much sp/exp you will gain so if you really, really want to get a precise amount you should add everything in your calculations.

[slimshady]

I tried taking my gap from 26 to a regular 9 gap and the exp and SP was still the same. your on crack.