# Allow or correct a circular reference

When a formula (formula: A sequence of values, cell references, names, functions, or operators in a cell that together produce a new value. A formula always begins with an equal sign (=).) refers back to its own cell, either directly or indirectly, it is called a circular reference. Microsoft Excel cannot automatically calculate all open workbooks when one of them contains a circular reference. You can remove a circular reference, or you can have Excel calculate each cell involved in the circular reference once by using the results of the previous iteration (iteration: Repeated calculation of a worksheet until a specific numeric condition is met.). Unless you change the default settings for iteration, Excel stops calculating after 100 iterations or after all values in the circular reference change by less than 0.001 between iterations, whichever comes first.

Locate and remove a circular reference

- If the
**Circular Reference**toolbar (toolbar: A bar with buttons and options that you use to carry out commands. To display a toolbar, press ALT and then SHIFT+F10.) is not displayed, click**Customize**on the**Tools**menu, click the**Toolbars**tab, and then select the**Circular Reference**check box. - On the
**Circular Reference**toolbar, click the first cell in the**Navigate Circular Reference**box. - Review the formula in the cell. If you cannot determine whether the cell is the cause of the circular reference, click the next cell in the
**Navigate Circular Reference**box.

** Note ** The status bar displays the word "Circular," followed by a reference to one of the cells contained in the circular reference. If the word "Circular" appears without a cell reference, the active worksheet does not contain the circular reference.

- Continue to review and correct the circular reference until the status bar no longer displays the word "Circular."

- When the
**Circular Reference**toolbar (toolbar: A bar with buttons and options that you use to carry out commands. To display a toolbar, press ALT and then SHIFT+F10.) appears, tracer arrows (tracer arrows: Arrows that show the relationship between the active cell and its related cells. Tracer arrows are blue when pointing from a cell that provides data to another cell, and red if a cell contains an error value, such as #DIV/0!.) appear that point out the cells that depend on the formula. - You can move between cells in a circular reference by double-clicking the tracer arrows.

Make a circular reference work by changing the number of times Microsoft Excel iterates formulas

- On the
**Tools**menu, click**Options**, and then click the**Calculation**tab. - Select the
**Iteration**check box. - To set the maximum number of times Microsoft Excel will recalculate, type the number of iterations in the
**Maximum iterations**box. The higher the number of iterations, the more time Excel needs to calculate a worksheet. - To set the maximum amount of change you will accept between calculation results, type the amount in the
**Maximum change**box. The smaller the number, the more accurate the result and the more time Excel needs to calculate a worksheet.