How to view preview of text size of user font in Android Studio?

No, there is no such way to preview the font scaling in the android studio as of now. but you can check out the material design for text scaling at < https://material.io/design/typography/the-type-system.html#type-scale > here you will some idea of how your text looks in runtime

As of about May 2020, This can now be done via the Layout Validation feature of Android Studio 4.0. This allows you to view different Font Sizes, devices and even see your layouts from the perspective of someone with color blindness.