With automatic calculation, a recalculation is triggered whenever there is any change in a cell/value that affects formulas (more so with volatile formulas). With worksheets that are loaded with a lot of data and formulas, this recalculation can waste a lot of time (and most of the time it is unnecessary) and make the workbooks slow.
To save time, we can change the calculation setting to manual. To do this:
- In Excel 2010/13: Go to File –> Options.
In Excel 2007: Go to Menus –> Tools –> Excel Options.
- In Excel Options, select Formulas.
- In Formulas options, change calculation options to Manual.
When manual calculation is selected, you need to manually force a recalculation by pressing F9 key.