How to Fix Negative Results in an Excel What-If Data Table
Question details
The user needs to resolve an issue where an Excel two-variable What-If Data Table is outputting negative values instead of the expected positive monthly loan repayments.
- Product
- Microsoft Excel
- Device & OS
- not provided
- Scenario
- Performing a price-sensitivity analysis on monthly student loan repayments using a two-variable What-If Data Table.
- Observed behavior
- The What-If Data Table returns negative values for the monthly repayments instead of calculating them as positive figures.
Ensure that your base calculation formula is working correctly outside of the data table. A data table simply repeats the logic of your source formula, meaning any sign errors or logic flaws in the original calculation will carry over to the entire table.
Verify Cash-Flow Signs in the Base Repayment Formula
Ensure the underlying formula feeding the data table calculates correctly and uses consistent signs for cash inflows and outflows.
In Excel, financial functions like PMT treat cash outflows (payments) as negative numbers and cash inflows (loans received) as positive numbers. If your base formula outputs a negative number, the entire data table will mirror this.
Select the single output cell that calculates the monthly student loan repayment, which acts as the reference for your data table.
Check the formula in the formula bar. If it uses the PMT function, add a minus sign (-) directly after the equals sign (e.g., =-PMT(...)) or before the Present Value (PV) argument to force the output to be positive.
Confirm that your base formula correctly references the original input cells for salary and savings ratio without hardcoding any variables.
Rebuild the What-If Data Table with Correct Input Mappings
Recreate the data table to guarantee the row and column input cells are assigned to the correct variables, as reversing them can cause illogical or negative results.
Perform What-If Analysis Easily with WPS Spreadsheet
WPS Office provides a robust, free spreadsheet tool that fully supports What-If Analysis, Data Tables, and complex financial formulas. You can easily model student loan repayments and price-sensitivity analyses with an intuitive interface that seamlessly handles Microsoft Excel files.
- 1. Open your workbook: Launch WPS Spreadsheet and open your financial modeling workbook.
- 2. Check your base formula: Ensure your repayment formula uses the correct positive or negative signs for cash flows.
- 3. Access What-If Analysis: Highlight your data table range, navigate to the 'Data' tab, and click 'What-If Analysis' followed by 'Data Table'.
- 4. Define inputs and generate: Assign your Row and Column input cells appropriately, then click 'OK' to generate accurate, positive repayment results.
Frequently Asked Questions
Why does the Excel PMT function return a negative number by default?
By default, financial functions like PMT in Excel adhere to standard accounting practices, representing cash outflows (like loan payments) as negative numbers and inflows (like the initial loan received) as positive numbers. To display the payment as a positive figure, simply place a minus sign before the PMT function.
How do I fix a Data Table that shows the exact same value in every cell?
This typically occurs when your Excel calculation options are set to 'Automatic Except for Data Tables' or 'Manual'. To fix this, go to the Formulas tab, click Calculation Options, and change the setting to 'Automatic'. The data table will instantly refresh and show the correct varied results.
Does it matter which variable is the row input and which is the column input in a two-variable Data Table?
Yes, it is critical. The 'Row input cell' must correspond to the source variable for the values listed across the top row of your table, and the 'Column input cell' must match the source variable for the values listed down the left side. Swapping them will result in inaccurate calculations.
Can I undo a Data Table calculation if I make a mistake mapping the input cells?
You cannot undo a Data Table calculation using the standard Undo button or Ctrl+Z. Instead, you must select all the result cells inside the data table (excluding your headers and the top-left formula cell), press the Delete key to clear the array, and then recreate the data table.
