Really simple questions

[Mr. Pozzer]

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP1 ($60.70)
MP2 ($31.20)
MP3 ($16.65)
Hero ($58.85)
Button ($31.15)
SB ($9.50)
BB ($31.75)
UTG ($27.45)
UTG+1 ($70.35)

Preflop: Hero is CO with 9[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/club.gif[/img].
<font color="#666666">5 folds</font>, <font color="#CC3333">Hero raises to $1.5</font>, Button calls $1.50, <font color="#666666">1 fold</font>, BB calls $1.

Flop: ($4.75) T[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, <font color="#CC3333">Hero bets $3.5</font>, <font color="#CC3333">Button raises to $10.5</font>, BB folds, Hero calls???

Assume the hand ends when I make my call. Can you show me the equation of how to get how much real $$$ I can call up to, to make this call profitable against a range that I have .310 equity against.

I got that I can call up to $5.81 to break even on my call. Is this right? (.31)*(18.75)? 18.75 is the pot before I call.

Seeing that my immediate odds are 2.68:1 I would guess that I'm very off here, please help me.