There is a lot more to it too, remember the market has been down. I would recommend contacting a local agent or Realtor to show you comps, do a complete CMA. See where you are at, if not, you can also pay for an apprasial to be done but if you are going to do that, might as well do it through your lender to see if you can meet apprasial value.
The market has been down, if you don't meet it now, in time, if or when the market stops falling and starts to increase (could be awhile from now) on average 4-5% equity is or was considered average before the big boom we had.
Best of luck.