Solve Equations in Excel using Solver Add-in Solver Add-in is a powerful and useful tool of Excel which performs calculations to give the optimal solutions meeting the specified criteria.

The Solver add-in is included by default in Microsoft Excel. You only need to activate it to load it. Learn how to load Solver add-in in Excel if it is not showing.

Excel can solve for unknown variables, either for a single cell with Goal Seek or multiple cells with Solver.