Theory - Equity and Pot Odds facing 2 all ins

[HiLo]

I got into an interesting hand today and it made me realise that I am lacking some theory in these spots so I thought I'ld post it up in BC, because a good answer probably belongs here.

In this hand the button and small blind are both huge donks. BB is a semi-decent reg who squeeezes a lot. He knows I am raising relatively wide in the cutoff but probably won't squeeze with total trash because of the donks, so I am initially estimating a wide value range(something like ATs+, AJ+, KQs, 99+). So I 4bet as I am holding blockers and try and induce a fold.

When he shoves I reckon his range is JJ+/AK only, so if we are heads up then the 3:1 pot odds would make this a call. But here the button has also gone all in. His range will include a lot of aces so my equity has reduced.

How do I go about figuring out the odds I need to call here?
(edit: obv I can do this in poker stove after the event but, am looking for a quickie shortcut to use in the heat of battle...)

No-Limit Hold'em, $0.50 BB (6 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com
Button ($19.65)
SB ($71.70)
BB ($50.95)
UTG ($50.75)
MP ($60.10)
Hero (CO) ($50)
Preflop: Hero is CO with A, Q
2 folds, Hero bets $1.50, Button calls $1.50, SB calls $1.25, BB raises $7, Hero raises $17.50, Button raises $18.15 (All-In), 1 fold, BB raises $43.45 (All-In), Hero folds but doesn't know how to estimate odds / Eq quick enough)