You would need to get a "Net Proceeds" on the house. This will show what it sells for, minus excise taxes, commissiones, etc. The remainder is what you get to keep, based on it selling for the market price.
Of course, the market is what a willing buyer would pay for it. Get a good agent to recommend a sales price for you. And, of course that will depend on when you sell it. Today is not the best time to sell, if you can wait until Feb, March, April timeframe. Of course, if you aren't wanting to sell, and this might be a good time to get a valuation of the home, since we are moving into the slowest time of the year, when prices seem to soften the most.
BTW, Capital Gains are only a consideration if you earn over $250,000 on the sale, $500,000 for the two of you. And, if you sold it and bought a new home, there would be no consequence to you.