When it comes to sizing cards in Kanban Zone, we keep it simple by using T-Shirt sizes. If you wish to use a different way to size your cards, then you can create a custom field with your own set of values.
1. Click on a card.
3. Select the size (S, M, L, XL).
If your plan is Professional or Enterprise, you will be able to edit the values shown in parenthesis in the screenshot above. Simply click the Edit Sizes link at the bottom of the menu to access the Custom Definitions organization setting. This means that these values will be shown on all your boards as the standard for your entire organization.