Question

What is Stored Powers base power if Eevee uses its z-move?

Answer 1

Extreme evoboost raises stats by 10 total stages. Stored power's base power is 20+20*s, where s is the total number of positive stages. So if there are no other stat changes, stored power's base power is 20+20*10, which is 220.
source
source

Comments

I definitely trust you over me.
Does this mean that the information we have on this website is wrong? Or (more likely, tbh) did I just screw up the calculation, because if so then I need to stop answering these type of questions :p

---

You screwed up the calculation. The formula 20*(number of stat increases)+20 is right; you just got the wrong number of stat increases. Extreme Evoboost boosts 5 stats by 2 stages each, so the total number of stat increases is 2*5, which is 10.
If you first add 5 stat boosts and then double them, then it can work if you do it right. But in your answer, you also doubled the +20 at the end, which is wrong.

---

Good to know. I'll just hide my answer then.
Thanks.