Use percentage without a number to indicate a general size. In product documentation, use the percent symbol (%) with a number to indicate how many out of 100, such as 20%. Without a number, spell out percent in text.
Examples
Ensure that the packet loss does not exceed 3%.
The chart displays the percentage of total memory that the server uses.
Marketing content and internal publications
Spell out percent in text. Use the percent symbol in charts and graphs.
