Your capital gain is calculated by subtracting your adjusted cost basis (i.e. original purchase price + improvements made - depreciation) from your net selling price (i.e. contract sales price - expenses of the sale).
Depending on when you purchased the property and placed it into service (i.e. did you depreciate using a non-MACRS method) you may also have some depreciation recapture. This means some of the gain may be treated as ordinary income.
If you have suspended losses (i.e. rental losses you could not deduct because your income was too high) they will become deductible in the year of sale.
Right now you have an estimated gain of $176,000 ($235,000-$59,000). However, this gain will change depending on your selling expenses incurred, depreciation taken and improvements you have made and capitalized during your ownership of the property. If you can give me those numbers I can calculate a gain.
By the way, any gain you recognize as a result of the sale will be considered as long-term capital gain subject to a maximum tax rate of 15%. Your gain is considered to be long-term if you have owned the property for more then one year. Otherwise the gain would be considered as short-term and taxed as ordinary income.
I am assuming you have not lived in the property as your principal residence for any of the last five years. If you have lived in the property for any 2 of the last five years (as of the date of the sale), you may be eligible to exclude up to $250,000 of the gain if you filing as a single (up to $500,000 if MFJ). Please let me know if that is the case.