Formulas

Well, I'm doing one tool but I'm having some problems with some formulas. I can't find a good formula for exp/h and sp/h statistics. Tried a lot of stuff but can't find an accurate ones. Someone have an idea about it?

Thanks in advance

#Moved to "SRO Coding Corner"

Ok during this time I've already made my own formula. For short periods of time seems accurate, not tested for long time periods. If someone gets stucked on the same problem as me, here you are my formula, might can help you all:

SP per minute
spmin = (60*sptotal)/sec

SP per hour
sphour = (3600*sptotal)/sec

Where sptotal = currentsp - startingsp and sec is a value which increases every second starting from 0
If you think is wrong please tell me, and if you can, suggest something better, I suck at maths XD