Goal Seek and Solver are Excel's powerful what-if analysis tools that work backwards from desired results. While regular formulas calculate outputs from inputs, these tools find the inputs needed to achieve specific outputs.
Understanding Goal Seek
Goal Seek finds the input value needed to achieve a specific result. It answers questions like "What sales volume do I need to break even?" or "What interest rate gives me this monthly payment?"
When to Use Goal Seek
Single variable problems
Finding breakeven points
Determining required values
Simple reverse calculations
Goal Seek Limitations
Only adjusts one cell
Only targets one result
No constraints possible
Simple trial-and-error approach
Using Goal Seek
Step-by-Step Process
1. Set up your formula (the formula you want to achieve a certain result)
2. Go to Data → What-If Analysis → Goal Seek
3. Set cell: The cell containing your formula
4. To value: Your target result
5. By changing cell: The input cell to adjust
6. Click OK
Example 1: Break-Even Analysis
Setup:
Cell B1: Price per unit = $25
Cell B2: Variable cost = $10
Cell B3: Fixed costs = $5,000
Cell B4: Units sold (unknown)
Cell B5: =B4(B1-B2)-B3 (Profit formula)
Goal Seek Settings:
Set cell: B5
To value: 0 (break-even)
By changing cell: B4
Result: Units needed to break even
Example 2: Loan Payment Analysis
Find the loan amount affordable with a specific payment:
Cell B1: Interest rate = 5%
Cell B2: Loan term = 30 years
Cell B3: Monthly payment = $1,500
Cell B4: =PV(B1/12,