Information
ISFORMULA function: catch hardcoded manual overrides in calculated columns
Audit financial models with ISFORMULA to spot cells where someone typed a static number over a live formula.
Why hardcoded overrides are silent model killers
During last-minute budget edits, a reviewer may type 300 directly over =Qty*Price in one row. Today the total looks fine; next month Qty changes and that row silently fails to update.
ISFORMULA(reference) inspects the cell itself rather than its result, returning TRUE if the cell starts with = and FALSE if it holds a static number, text, or blank.
| Qty (A) | Price (B) | LineTotal (C) | ISFORMULA(C) |
|---|---|---|---|
| 10 | 25 | =A2*B2 (250) | TRUE |
| 12 | 25 | 300 (hardcoded number!) | FALSE |
| 8 | 25 | =A4*B4 (200) | TRUE |
Flag manual overrides in an audit check column
IF(ISFORMULA(C3), "Formula OK", "Manual Override") immediately pinpoints C3 even though 12 * 25 happened to equal 300 at the time it was typed.
=IF(ISFORMULA(C3), "Formula OK", "Manual Override")Verify formula cells return TRUE even if they output text or errors
ISFORMULA checks how the cell is stored, so C2 (=A2*B2) returns TRUE regardless of its calculated value.
=ISFORMULA(C2)Try the example
Use the original values or change them to test your understanding.