---
title: underlineThickness
framework: appkit
role: symbol
role_heading: Instance Property
path: appkit/nsfont/underlinethickness
---

# underlineThickness

The thickness to use when drawing underlines with the font.

## Declaration

```swift
var underlineThickness: CGFloat { get }
```

## Discussion

Discussion The value in this property is determined by the font’s AFM file.

## See Also

### Getting Underline and Italic Metrics

- [italicAngle](appkit/nsfont/italicangle.md)
- [underlinePosition](appkit/nsfont/underlineposition.md)