The formula field is one of the best features of the Salesforce platform for admin (and developer). Despite the limitation and restrictions, it still serves a lot of benefits.
- You can’t use long text area, encrypted, or description fields in formulas.
- The value of a field can’t depend on another formula that references it.
- You can’t delete fields referenced in formulas. Remove the field from the formula before deleting it.
But, where the formula field can and cannot be used?
Page Layout - Yes, including dynamic form, search layout, and compact layout. But the formula field is not searchable.
Report - Yes, including use as a filter
List View - Yes, including use as a filter
Validation Rule - Yes, except that you can't set the error message location at a formula field
Approval Process - Yes
Sharing Rule - No, the criteria based sharing rule does not support by formula field, you can vote on the idea here, here, and here; here is the original idea but has been marked as partially delivered although the item delivered has nothing to do with sharing rule.
Email Template - Yes
Flow - Yes
SOQL - Yes
If there are other places we can or cannot use formula fields, feels free to comment below this blog.