Goal Seek lets Excel work backward. You choose a formula result you want, then tell Excel which single input cell it may change to reach that target.
Does this affect you?
Use this for Excel for Microsoft 365, Excel 2021, and Excel 2019 on Windows or Mac when one input needs to be solved from one formula result. Goal Seek is not available in Excel for the web.
Run Goal Seek for one input
The same structure works for payments, profit targets, rates, quantities, and other formulas.
- Set up a formula that depends on the input you want Excel to solve.
- Click the formula result cell.
- Open Data > What-If Analysis > Goal Seek.
- Confirm Set cell is the formula cell.
- Enter the desired result in To value.
- In By changing cell, choose the input cell Excel is allowed to adjust.
- Click OK.
- Choose OK to keep Excel’s result, or Cancel to return to the old value.
For payment formulas, remember that Excel financial functions may show outgoing payments as negative numbers, so the target may need to be negative.
Fix Goal Seek when it cannot find a solution
Goal Seek uses an iterative search and can fail when the target is impossible or the starting value is poor.
- Check that the target value is mathematically possible.
- Enter a starting value closer to the likely answer in the changing cell.
- Check formula settings for iterative calculation and reasonable maximum iterations.
- Run Goal Seek again.
If it still fails, test with an easy target to confirm the formula setup works, then adjust the target.
More control
Use Solver for multiple inputs
Goal Seek changes one cell only. If several variables, limits, or constraints are involved, enable the Solver add-in and solve the model from the Data tab.
Save original values first
Goal Seek writes the answer directly into the changing cell. Copy the original inputs elsewhere if you need to compare before and after.
Check formula dependency
The changing cell must affect the set cell. If the target formula does not depend on that input, Goal Seek cannot solve anything.
Sources
- Microsoft Support – Use Goal Seek to find the result you want by adjusting an input value (2025)
- Microsoft Support – Define and solve a problem by using Solver (2025)
- Microsoft Support – PMT function (2025)