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.

Excel can solve equations through several of its mathematical functions, but the single Excel tool that works on the largest variety of equations is the program's Solver Add-in.

In this guide, I'll show you how you can use it to solve real-world problems. To follow along as you read this guide, download a free copy of the Excel workbook used in the examples.

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