A circular reference can occur when a dependency references a dependent in a chain of calculations. When this occurs, it is impossible to evaluate the value of any of the calculations in the chain, and all calculations in the chain are assigned the Circular Reference quality.

The simplest form of circular reference is when a calculation references itself. For example, if the definition of X is [X], then X has a circular reference as it is dependent on itself.

The following is an example of a circular reference chain: