When you need to modify an Excel spreadsheet without triggering any new calculations, you turn on manual calculation mode. This is one of the oldest features in Microsoft Excel, and after three decades, it still suffers from one awkward problem—Excel doesn’t indicate when a change you’ve made in manual mode affects an existing calculation. If you aren’t careful when editing a spreadsheet in manual calculation mode, you can end up with incorrect or “stale” values.
To solve this problem, the latest Windows Beta build adds new “stale value formatting” to Excel. It’s a pretty simple idea; strikethrough formatting will be applied to any values that become “stale” when you tinker in manual calculation mode. Additionally, a small warning box will appear when you click a cell with a stale value. This box expands into a context menu with several useful options, including a tool to recalculate the cell’s value (and an option to disable stale value formatting).
Stale value formatting will also apply to automatic calculation mode, but only in special circumstances. If you hit the escape key while running a complex calculation, for example, you can end up with a stale cell. Still, the feature is most helpful when in manual calculation mode.
To be clear, Excel always tracked stale values. But users had no way of checking which cells were stale, or how many. As Microsoft notes, manual calculation mode predates Excel and was originally introduced by the macOS program VisiCalc in 1979—it’s a seriously overdue feature.
Unfortunately, there doesn’t appear to be a way to customize stale value formatting. You can’t tell Excel to highlight stale cells in red, for example. So, you’ll still need to keep your eyes peeled when working on large spreadsheets, as strikethrough text may blend in with all the other horizontal lines in Excel.
Stale value formatting is currently limited to Excel’s Beta Channel on Windows. The feature will exit beta within the next few months, at which point, it will be available to all Excel on Windows users. Microsoft hasn’t confirmed a timeline for when we can expect the feature on the macOS and web apps.
Source: Microsoft