check my math: KK preflop

[br.bm]

Hi
are there any mistakes in my calculation?

(ATC = any two cards but aces.
I know that KK doesn't have 80% equity vs any two.)

Here is the problem:
--------------------
eff stacks 100BB
Hero KK

Preflop:
Hero: Raise to 5BB
Villian: Reraise to 15BB
Hero: 3bet 50BB
Villian: 4bet All in

Lets assume:
KK equity vs AA is 20%
KK equity vs ATC is 80%

EV vs AA:
0.2 * 1.5 s - 0.8 * 0.5 s = -0.1 s
EV vs ATC:
0.8 * 1.5 s - 0.2 * 0.5 s = +1.1 s
(s = stacks)

If we call 12 times and villian has ATC once we are 0EV.
This means if 1/12 of his range is ATC we have to call.
1/12 = 0.083 or 8.3%
100 % - 8.3 % = 91.7%

If we are 90% sure that villian has AA a call is +EV.