This plugin uses date picker field on front-end for adding date of birth, and converts birth date into age number. Input date format must be: mm/dd/yyy Ninja Forms plugin must be install prior Ninja Forms Age Field extension.

It simply adds input field with date-picker on front-end, visitor is required to choose his birth date from calendar. When form is submitted, visitor age will be returned, instead of full date.

This section describes how to install the plugin and get it working.

Upload ninja-forms-extension-age-field.zip file through WordPress admin, or

FTP: 1. Upload ninja-forms-extension-age-field folder to the /wp-content/plugins/ directory 2. Activate the plugin through the 'Plugins' menu in WordPress