Originally Posted by Mike_73
I have no idea on how to change font size with calibre (others will tell you more here).
What you can do despite changing font with calibre is to change the font of your book in a wordprocessing program.
If you increase font size in the program you should have a font size big enough for reading once the book is converted to its initial file format.
Thanks! I'll give that a try. Just need it a teeny bit larger.