Virindi XPHelper helps determine how much your character's primary attributes (strength, endurance, etc) should cost to raise based on the costs of your skills and secondary attributes (health, stamina, mana).
To determine this, the following algorithm is used for each primary attribute type:
foreach (skill or secondary attribute)
if (this skill depends on the current primary attribute)
optimal_cost = optimal_cost + cost_to_raise_this_skill / attribute_divisor_for_this_skill