In worksheets that have a large amount of formulas, this behavior can drastically slow down your macros.
If your workbook is formula intensive, you may not want Excel to trigger a recalculation every time a cell value is altered by your macro. Calculation property to tell Excel to switch to manual calculation mode.
When a workbook is in manual calculation mode, the workbook will not recalculate until you explicitly trigger a calculation.
Unfortunately, each time Excel redraws the screen, it takes up memory resources.In most cases, you don’t need Excel using up resources to redraw the screen each time your macro performs some action.