Excel Performance Problems

How to Fix Incorrect Excel Formulas and Slow Workbook Performance

Natalie Taylor Oct 20, 2026 868 views

Question details

The user is experiencing incorrect or missing results from Excel formulas, along with significant performance slowdowns and application instability in a large workbook.

How to Fix Incorrect Formula Results and Slow Performance in Excel

Product: Microsoft Excel
Device & OS: macOS
Scenario: Working with a large, complex Excel workbook containing VBA macros, circular references, and dynamic formulas.
Observed behavior: Certain formulas like SUMIFS return incorrect values, and the application becomes increasingly slow during extended use. Disabling iterative calculation exposes underlying errors.

Before you start

Before making structural changes or deleting formulas, save a local backup copy of your workbook to your Mac rather than editing it directly from a OneDrive link.

Solution 1Recommended

Resolve Circular References and Disable Iterative Calculation

Circular references cause Excel to calculate in an infinite loop, which severely impacts speed and causes formulas to return unreliable results.

Iterative calculation forces Excel to recalculate a sheet until a specific numeric condition is met. When turned on accidentally, it hides circular reference warnings and causes unpredictable formula outputs.

Disable Iterative Calculation

Go to Excel > Preferences (on Mac) or File > Options (on Windows). Select Calculation, and uncheck the 'Enable iterative calculation' box. Click OK.

Locate Circular References

Navigate to the Formulas tab on the ribbon. Click the arrow next to Error Checking, and hover over Circular References. The submenu will display the exact cell addresses causing the loop.

Fix Dependencies

Click on the cell addresses provided in the Error Checking menu to inspect them. Adjust the formula so it does not refer back to its own cell, either directly or indirectly.

Resolve Circular References and Disable Iterative Calculation

Tip: Fixing circular references often immediately restores normal calculation speeds and corrects downstream formula errors.

Solution 2

Optimize Complex Formulas and Volatile Functions

Heavy use of dynamic, volatile, and complex formulas like SUMIFS over unnecessarily large ranges bogs down Excel's calculation engine.

Solution 3

Reduce File Size and Formatting Overhead

Excessive formatting applied to blank cells drastically increases workbook size and causes instability during extended use.

Efficiently Handle Large Workbooks

Optimize Large Spreadsheets and Formulas in WPS Spreadsheet

WPS Office offers a highly efficient Spreadsheet application designed to handle large datasets, complex formulas, and multi-sheet layouts smoothly. Built with excellent compatibility for Microsoft Excel formats, it helps you process data correctly without system crashes.

1. Open your file: Launch WPS Spreadsheet and open your slow or problematic .xlsx workbook.
2. Check for errors: Navigate to the Formulas tab and click Error Checking to scan for and resolve hidden circular references.
3. Enable manual mode: Go to Formulas > Calculation Options and select Manual to prevent interface lag while editing complex layouts.
4. Clean up formats: Use the Clear tool under the Home tab on unused rows and columns to remove unnecessary formatting and reduce file size.

Handles complex calculations and large datasets with optimal memory usage100% compatible with Microsoft Excel (.xlsx) formats and formula syntaxBuilt-in error checking for easily resolving circular referencesLightweight application that consumes fewer system resources on macOS and Windows

microsoft office alternative - wps office

Frequently Asked Questions

Why does my SUMIFS formula return an incorrect result?

SUMIFS can return incorrect results if the criteria ranges and sum ranges are not exactly the same size. Additionally, hidden circular references elsewhere in the sheet can disrupt the entire calculation chain, leading to missing or false outputs.

What is iterative calculation in Excel?

Iterative calculation allows Excel to calculate formulas that refer to their own cells repeatedly until a specific condition is met. However, if left enabled accidentally, it will suppress warning messages and mask formula logic errors.

How can I speed up a slow Excel workbook on a Mac?

You can improve performance by saving the file locally instead of editing on OneDrive, removing excessive cell formatting on blank rows, minimizing the use of volatile formulas (like INDIRECT), and switching the calculation mode from Automatic to Manual.

Excel & Data Problems