One of the preliminary steps in designing and laying out a page is formatting the type. Many important decisions have to be made, including choosing the point size of your type, line length, line spacing, alignment, style of the paragraph indents, and more, depending on the piece.
Don't let your software's default settings determine these important design characteristics! Your choices should be made with consideration for your design goals and the demographics of your audience, in combination with aesthetics and what works best with the design and composition as a whole.
Deciding what size to set your type is a visual thing, but there are some guidelines that can help you make that decision.
Let's talk about text settings first. The primary consideration when setting text is usually readability. Assuming you select a font that was designed and intended for smaller settings, the average range for text settings is somewhere between 9 and 12 point and sometimes up to 14 point. Anything smaller can be hard to read in longer settings. Much larger than 12 to 14 point can become a strain on the eyes for any length of copy for the average reader.
The size you select is somewhat dependent on the typeface you choose, as the actual cap height and x-height varies from font to font. The x-height of a font affects its legibility and will make different typefaces look larger or smaller at the same point size. The length of the text should also be considered, ...