Using Data Validation to Limit Data Entry

Gary has a worksheet that people in his office use for data entry. He wants to make sure that in a particular cell they can only enter a numeric value. He wonders how to stop them from entering other entries—like text or dates or times—in the cell.

The easiest way to do this is to use Excel's data validation feature. This feature allows you to define the parameters of what can be entered in a cell. Follow these steps:

1. Select the cell you want used for inputting a value.
2. Display the Data tab of the ribbon.
3. In the Data Tools group, click the Data Validation tool. Excel displays the Data Validation dialog box. (Click here to see a related figure.)
4. Using the Allow drop-down list, choose either Whole Number or Decimal, depending on which type of numeric input you want to allow. Excel changes the controls available in the dialog box.
5. Using the Data drop-down list, make sure Between is selected.
6. Enter in the Minimum and Maximum boxes the lower and upper bounds of what you want users to enter in the cell.
7. On the other tabs of the dialog box, enter an input message and an error message, if desired.
8. Click OK.

People can now enter only a numeric value within the range you specified. The one exception to this is dates and times. Since they are maintained internally, by Excel, as numbers, it is possible to enter a date, provided the date is parsed into a numeric value that is within the range you specify.

For instance, if you set up data validation to only allow values between 20,000 and 21,000, then someone could enter a date of 6/11/1956 because Excel parses the date to the whole number 20,617. The best way to handle dates and times is to format the cell so that it uses a numeric format, which will stop Excel from displaying dates and times.