According to OverTheCap, the Seahawks are expected to have almost $33 million in cap space when the 2017 league year begins in March. That is only as estimate though, since the salary cap has not been officially set.
In fact, that number is almost certain to go up. The preliminary figured the league announces in November is always extremely conservative. It is for planning purposes, and represents a minimum value for what the salary cap might be. The final salary cap figure could easily be $5 million or more above that.
$33 million is a lot of cap space.