You cannot change the size of the font used in Microsoft Dynamics CRM, but you can change your browser setting so the font appears bigger or smaller by doing one of the following:
1. Use Ctrl + and Ctrl - to control the zoom feature in Internet Explorer
2. Change the screen resolution on your computer eg with a lower resolution your text will appear larger
Adding custom fonts in Dynamics CRM directly is not possible but there is a workaround to add custom fonts in CRM using Customizations option.
As indicated by Lu Hao, you may mention your requirement in the below page and will be taken into consideration based on the severity and number of customers requesting for it -
experience.dynamics.com/.../
