To see the formulas instead of their results, press Ctrl + {`} or click Formulas → Show Formulas. To show a single formula next to its result, use FORMULATEXT.
Table of Contents
The data

1. Show Formulas button
Formulas → Formula Auditing → Show Formulas. Click again to switch back.


2. Ctrl + `
The grave accent key is to the left of 1. Press Ctrl + {`} to switch between formulas and results.

It works per sheet, and columns widen while formulas are shown.
3. FORMULATEXT
=FORMULATEXT(E5)Shows E5’s formula as text, while E5 keeps showing its result. Useful for training sheets and documentation. In Excel 365, =FORMULATEXT(E5:E10) spills all of them.

4. Apostrophe
Type an apostrophe before the equals sign, '=SUM(B2:B5), to store the formula as text so it shows instead of calculating.

Print the formulas
Turn on Show Formulas, then Page Layout → Print Titles → Sheet and tick Row and column headings, so the printout shows cell addresses too.
Find every formula
Press Ctrl + G → Special → Formulas to select all formula cells, then give them a fill colour.