Excel Running Slow? 10 Fixes to Speed Up Your Spreadsheets

1. Volatile Functions

Functions like INDIRECT, OFFSET, NOW, TODAY, and RAND recalculate every time anything in the workbook changes. One INDIRECT formula isn't a problem — thousands are.

Fix: Replace INDIRECT with INDEX/MATCH or XLOOKUP. Use static dates instead of TODAY() where real-time isn't needed.

2. Array Formulas Over Large Ranges

SUMPRODUCT, array formulas (Ctrl+Shift+Enter), and dynamic array functions operating on entire columns (A:A) can be extremely slow.

Fix: Define specific ranges (A1:A10000) instead of entire columns. Break complex calculations into helper columns.

3. Too Many Conditional Formatting Rules

Conditional formatting recalculates constantly. Hundreds of rules, especially with formulas, kill performance.

Fix: Home → Conditional Formatting → Manage Rules → delete unnecessary rules. Use fewer rules with broader ranges.

4. Bloated File Size

Files grow when you copy/paste from other workbooks, accumulate formatting, or have unused defined names.

Fix: Clear unused cells: Ctrl+End shows the “used range” — if it goes way beyond your data, select empty rows/columns and delete them. Save and reopen.

5. External Links

Links to other workbooks, especially on network drives or closed files, cause delays while Excel tries to fetch data.

Fix: Data → Edit Links → Break Links for links you don't need. Copy/paste values to remove formulas that reference external files.

6. Automatic Calculation

Excel recalculates everything with every change. In large workbooks, this creates constant delays.

Fix: Formulas → Calculation Options → Manual. Press F9 to calculate when needed. Remember to switch back for final use.

7. Heavy Data Validation

Data validation lists referencing other sheets or using formulas add calculation overhead.

Fix: Use named ranges for validation lists. Keep list sources on the same sheet when possible.

8. Images and Objects

Large images, many shapes, or embedded objects bloat files and slow scrolling.

Fix: Compress images: select image → Picture Format → Compress Pictures. Delete hidden objects: Home → Find & Select → Go To Special → Objects.

9. Named Ranges Gone Wrong

Workbooks can accumulate invalid named ranges over time, especially from imports.

Fix: Formulas → Name Manager → look for #REF! errors and delete invalid names.

10. Add-ins

Some add-ins run code on every calculation or selection change, slowing everything down.

Fix: File → Options → Add-ins → disable add-ins one by one to identify the culprit.

Official Resources

• Speed up Excel — Microsoft performance tips
• Reduce file size — shrink large workbooks