QUOTE(Rei-Tenshi @ Oct 19 2010, 19:00)

All my pieces are 20-24. What would 5 pieces of 30% mitigation amount to?
Did you also add the mitigations from maxed spell tiers (10), white aura (2.5), rainbow aura (1) ?
yes.
250 proficiency adds +25% to stats of equipment.
24*1.25=30
You can try using sonic's cal, it's very easy just add the 5 values to get the answer. Btw I'm not certain but I think even with 5 pieces of 32% aren't enough.