iOS Font Sizes
Below are the font and point sizes used by iOS at the default sizing level. You can read more, including about the accessibility curves, on Apple’s documentation.
| .extraLargeTitle iOS 17 |
36.0 | SFUI-Bold |
| .extraLargeTitle2 iOS 17 |
28.0 | SFUI-Bold |
| .largeTitle | 34.0 | SFUI-Regular |
| .title1 | 28.0 | SFUI-Regular |
| .title2 | 22.0 | SFUI-Regular |
| .title3 | 20.0 | SFUI-Regular |
| .headline | 17.0 | SFUI-Semibold |
| .subheadline | 15.0 | SFUI-Regular |
| .body | 17.0 | SFUI-Regular |
| .callout | 16.0 | SFUI-Regular |
| .footnote | 13.0 | SFUI-Regular |
| .caption1 | 12.0 | SFUI-Regular |
| .caption2 | 11.0 | SFUI-Regular |
Usage
Use preferredFont(forTextStyle:) or scaledFont(for:) with the UIFont.TextStyle constants instead of hard-coding font values in your code.
// update when the user changes their settings
label.adjustsFontForContentSizeCategory = true
label.font = UIFont.preferredFont(forTextStyle: .body)
You can use a modified version of the font with the same scaling:
// for a custom font at the normal scaling
let adjustedFont = UIFont(name: "AmericanTypewriter", size: 17.0)
// for the system font, but starting at a different default point size
// this point size value must be defined as a constant, see below
let adjustedFont = UIFont.systemFont(ofSize: 16.0, weight: .regular)
// use the scaled font version so it still updates automatically
label.adjustsFontForContentSizeCategory = true
label.font = UIFontMetrics(forTextStyle: .body).scaledFont(for: adjustedFont)
NOTE: The current point size from preferredFont(forTextStyle:) already includes scaling. Using it as the starting point will produce double-scaled fonts at ridiculous point sizes.