Hey let me see if I can help you understand the general math(it can get more complicated, a resource like Melanocetidae posted is good for more exact, but Ill wlak you through a general process).

First you want to calculate each persons range(in %).  There are 7 people left to act, just glancing and assuming lets do something like this:

*Note I dont have a working laptop actually in my campuses library right now so no stove, Im going to speak in %'s, not knowing exaclty waht they equate too but shouldnt really matter.

MP1: 7%

MP2: 7%

HJ: 8%

CO: 8%

BTN: 9%

SB: 11%

BB: 13%

Lets just assume you think these are their ranges.  In order to make a rough estimate in the value you first want to calcualte the average calling range: (7+7+8+8+9+11+13)/7 = 9% (Which i semi planned to happen)

So now lets see how often we get called.  This is actually a little complicated, so lets start with the reverse, in how often we get folds.  The average person is folding 91% of the time(calling 9%).  So they all fold .91*.91*.91…… 7 times or .91^7 which is 51.7%(we will call it 52%).  So we get folds 52% of the time, and we take down about 2.5BBs(I am assuming there are antes).  So our expectation is +1.3BB(.52*2.5).

Just at a cursory glance you can see its almsot 50/50 in terms of folding and getting called.  Meaning if we wxpect to lose more than 1.3BB when called we are losing money.  

Since I dont have stove I will have to solve this semi differntly.  First I will calculate the pot when called(by one person, to factor in the odds of getting called in more than 1 spot is trickier).  

Note that two people have less stakcs then us, to adjust for this(alhough not entirely correct but accurate enough for us), I will assume the amount we lose is slightly elss then our stack, and the amount we win is slightly less than our stack, in this case Ill take away half a BB form each or 1 BB total, so instead of 14 BBs each side, ill treat it as 13.5BBs each side).

The pot is going to be 13.5+13.5+2.5(blinds) = 29.5  We dont want to lose more than 1.3 so we need to get back at least 12.2, but remember I skipped out the odds of getting called by more than 1 person earlier, so we should semi account for that now(again this isnt perfect but fine for generalized), so I will say we want back at least 12.8(so we dont want to lose more than .7).  So we need 12.8/29.5 = 43.4%.

Using pro poker tools, we have 41.01% agasint this range( so marginally -EV).

However my assumptions are just that, my assumptions, I just wanted to walk you through the math of shoving.

Hope this helps, let me know if you need more clarification.