#1MinuteTip Here is how you can get a standard field’s length in Salesforce. There are other mechanisms too, but this one will probably be the simplest.
1. Click on Gear icon -> Right click on Developer Console -> Click Open Link in New Tab
2. Click on Debug -> Open Execute Anonymous Window
3. Type the following command, check Open Log and click Execute. Replace the highlighted part of the code with the API name of the object and field that you want to get the length of.
System.Debug(Case.Subject.getDescribe().length);
4. In the log window, check “Debug Only” and the value that appears to the right of “DEBUG | ” is the length of the field.