Why Excel 2013 Formulas Stop Updating After Another Workbook Opens

Check the current calculation mode before rewriting the formulas. Excel’s calculation setting applies across the workbooks open in the same Excel instance. A workbook saved in Manual mode can establish that mode when it is the first ordinary workbook opened; later workbooks then use the same session setting.

That does not mean any manually saved workbook overrides an already-running Automatic session merely by opening second. Opening order, the current session, and later setting changes matter. Microsoft’s calculation-performance reference explicitly includes Excel 2013 and describes the first non-template, non-add-in workbook rule. Excel calculation performance.

Fix the immediate symptom safely

1. Save your work and consider the other open files. Switching to Automatic can start substantial recalculation in large models. Close unrelated sensitive or expensive-to-calculate workbooks before a practice experiment.
2. Inspect Formulas > Calculation Options. In Windows Excel, File > Options > Formulas > Workbook Calculation is another place to inspect the mode.
3. If Manual is selected unintentionally, choose Automatic. Allow calculation to finish.
4. Change one known input and check a small, predictable dependent result. A refreshed display once is not proof that subsequent edits will calculate automatically.
5. Save the corrected workbook only when the results and intended mode are right.

Current Microsoft guidance confirms that changing desktop calculation options affects all open workbooks. Recalculation settings and shortcuts.

If the workbook deliberately uses Manual for a long-running model, coordinate the change with its owner. Pressing F9 for an immediate recalculation can be appropriate, but it does not turn on Automatic.

Prove the opening-order effect with two disposable files

Use local synthetic .xlsx files. Do not use a production model, enable macros, or change startup files for this test. CSV cannot preserve a workbook’s calculation setting, so a downloadable CSV would not reproduce this issue.

Prepare the files separately

1. Close Excel completely after saving other work. Start a new blank workbook, select Automatic, and enter these three cells:

   Cell	Enter	Initial result
   A1	5	5
   A2	7	7
   B1	=SUM(A1:A2)	12

2. Save it as Auto-check.xlsx. Close Excel completely.

3. Start another blank workbook. Put the label Synthetic calculation-mode opener in A1, select Manual, and save it as Manual-start.xlsx. Close Excel completely again.

The SUM formula deliberately makes the expected answer obvious. There are no external connections, volatile functions, tables, or macros to confuse calculation with refresh. Microsoft SUM reference.

Run the Manual-first case

1. Open Manual-start.xlsx first in a fresh Excel session. Then use File > Open in that same Excel instance to open Auto-check.xlsx. Avoid opening a blank workbook first.
2. Inspect Calculation Options while Auto-check is active. Under the documented opening-order behavior, it should be Manual despite having been saved as Automatic.
3. In Auto-check, change A1 from 5 to 9. Do not save or press F9 yet. B1 should still show its previously calculated 12, although the arithmetic is now 9 + 7 = 16.
4. Press F9. B1 should become 16. Recheck Calculation Options: it should still be Manual.
5. Change A1 to 10. B1 should remain at 16 until you select Automatic; then it should become 17. A later input edit should update without F9.

These are expected checkpoints, not a record of a native test performed for this article.

Reverse the order

Close the practice files without saving these changed inputs or calculation settings, and quit Excel. Open the original Auto-check.xlsx first, followed by Manual-start.xlsx in the same instance. Calculation should remain Automatic. Changing Auto-check!A1 to 6 should give B1 = 13 without F9.

This contrast isolates session inheritance. Microsoft documents both directions and also notes that saving stores the current mode, not necessarily the mode the file had when you first received it. How Excel determines calculation mode.

When finished, restore Automatic for ordinary work. Keep the two original practice files unchanged if you want to repeat the experiment; saving Manual-start while Automatic is active would change the very condition it is meant to demonstrate.

F9, full calculation, and Automatic are different

Action in Windows Excel	Scope and purpose
F9 / Calculate Now	Recalculate changed formulas and their dependents across open workbooks
Shift+F9 / Calculate Sheet	Recalculate the active worksheet
Ctrl+Alt+F9	Force calculation of all formulas in open workbooks
Ctrl+Shift+Alt+F9	Recheck dependencies and force full calculation
Select Automatic	Make later relevant edits trigger recalculation

Use the least disruptive action that answers your question. Full calculation can be expensive and does not by itself make Manual mode permanent Automatic. On keyboards that repurpose function keys, use Excel’s Calculate commands or the appropriate Fn-key combination. Microsoft’s shortcut definitions.

If the experiment or real workbook behaves differently

• Auto-check updates immediately in the Manual-first test: inspect the selected mode first. A startup workbook, an existing Excel instance, a template, or code may have established or changed it. Stop at the observed result; do not assume the inheritance diagnosis has been proved.
• Opening a workbook second really does change the mode: that is not the basic first-workbook rule. A macro or add-in could change application settings. Keep the workbook’s security restrictions in place and ask its owner to inspect the relevant automation.
• The formula is visible as literal text: investigate a leading apostrophe, Text cell format, or Show Formulas. Those symptoms are not fixed by recalculation. Work on a copy before re-entering any formulas.
• An imported table is stale: calculation and external-data refresh are different operations. Recalculating formulas does not establish that a Power Query source has been refreshed.
• One result remains wrong in Automatic: inspect references, input types, errors, and circular dependencies. Manual mode is one possible cause, not a universal explanation.
• Automatic except for data tables is selected: the exception concerns What-If Analysis data tables, not ordinary formatted Excel tables. Confirm what the workbook actually uses before changing it.

Do not turn on iterative calculation or Set precision as displayed as a general repair. Neither diagnoses first-workbook inheritance; precision-as-displayed can permanently alter stored values. Microsoft’s precision warning.

Version and verification notes

The legacy evidence is Microsoft’s calculation-performance article, whose applicability explicitly includes Excel 2013. Current Windows help corroborates the session behavior and shortcuts. Newer Excel windows can look like separate applications while still sharing an instance, so different taskbar windows alone are not a reliable isolation test. This walkthrough does not establish Mac or Excel for the web behavior.

Not tested in Excel. Documentation was checked October 16, 2026. The sums 12, 16, 17, and 13 were independently calculated; the workbook opening order, UI, and stale-value behavior were not executed in a native Excel application.