Adding fields to the GIS attribute table

  1. In the ArcMap table of contents, right-click the correct layer and select Open Attribute Table. The Attributes dialog box is displayed.
    Note: If you’re in Edit mode in ArcMap, you must stop editing before you can add fields.
  2. In the Attributes dialog box, click the Options button and select Add Field.
  3. Specify the name of the field you’re adding in the Name field.
  4. Select the type of field from the Type list.
  5. Under Field Properties, enter the length of the field.
  6. Click OK.