Circular dependency detected in Google Sheets

A formula that points at its own cell lands as #REF!. Sheets cannot finish the value. That is a loop, not a missing range.

Recreate it on a blank sheet

1. Open a blank spreadsheet. In A1 type 10.
2. In A2 enter =A1+A2. The cell shows #REF!. The tooltip is Circular dependency detected. To resolve with iterative calculation, see File > Settings.

3. Two cells can loop the same way. In C1 enter =C2. In C2 enter =C1. Both cells show #REF!. Each formula depends on the other.

What is actually wrong

• =A1+A2 asks A2 for a value that includes A2. A2 is waiting on itself.
• C1 =C2 and C2 =C1 is the same cause split across two cells: each formula depends on the other.
• This #REF! is not a VLOOKUP index past the range, not a UNIQUE spill that would overwrite a cell, and not IMPORTRANGE waiting for Allow access. The references exist. They form a cycle.

The tooltip points at File > Settings; do not turn iterative calculation on for this error.

Fix

Remove the self-reference. Change A2 to =A1. The cell shows 10.

Leave C1 and C2 as they are so the two-cell loop stays #REF! on the sheet.

Point the formula at cells that do not depend on this cell.