Need to stop UDFs recalculating when unrelated cells deleted

Question

I\'ve noticed that my UDFs recalculate whenever I delete cells. This causes massive delays when deleting entire columns, because the UDF gets called for each and every cell

Answer 1

Inserting or deleting a row or column or cell will always trigger a recalc in automatic mode. (You can check this by adding =NOW() to an empty workbook and inserting or deleting things)

The question should be what (unexpected) circumstances flag a cell as dirty so that it gets recalced. There is a (probably incomplete) list of such things at http://www.decisionmodels.com/calcsecretsi.htm

Looks like I need to add some words about VBA UDFs (have not tested XLL UDFs
- they may behave differently since they are registered in a different way to VBA UDFs)