That all depends on the holding period and your taxable income.  

Short-term gains: If you held the stock for less than a year, the gains from the sale will be taxed as ordinary income. 

Long-term gains: If you held the stock for more than one year, the gains will receive preferential tax treatment. Capital gain may be taxed at 0% if you're in the 10% or 15% ordinary income tax brackets, taxed at 15% in the 25-35% brackets, and taxed at 20% if you are in the 39.6% ordinary tax rate. 

You may want to utilize this tax calculator to help estimate your tax liability for 2017. 

https://turbotax.intuit.com/tax-tools/calculators/taxcaster/