The Home tab in Microsoft Word 2010 and 2013 has everything you need to boost the size of text in an existing document or increase the font size of a new document. Pick a size from the Font Size drop-down menu, use the Increase/Decrease Font Size buttons or type a number above the menu to set the size.
Text Size in Word
Open the Font Size drop-down menu in the Font section to pick a new size. To change the size on existing text, select the text before picking a size.
Select text and press the Increase Font Size button to expand the text by one size setting, such as from 16 to 18. The neighboring button decreases the font by one size setting.
Type a number into the Font Size box to pick a size not found in the drop-down menu. Valid options include sizes between the displayed options, such as 17, half-sizes, such as 17.5 and sizes larger than the menu's highest setting of 72, such as 100.
Click the Font dialog box launcher in the corner of the Font section to see other font options. Press Set as Default Word's to set the current font as the default.
Increase the zoom level in the lower-right corner of Word to make text look larger without actually changing the font size. The zoom level won't affect how the document prints.
Text Size on the Desktop
Search for and open Make Text and Other Items Larger or Smaller using the Windows 8.1 Start screen.
Change the size of all items to affect both text and other desktop components, such as windows and icons.
Change the text size of individual desktop items, such as menu bars or tooltips, using the drop-down menus. Check Bold to bold the selected item's text.
Press Apply after changing all the components you want to make larger.