# `GSFont scaleBy:`

*Instance Method*

Scales the font by a factor.

## Declaration

```swift
func scale(by scale: CGFloat)
```

```objc
- (void) scaleBy:(CGFloat) scale;
```

```python
scaleBy_(scale: float)
```

## Parameters

- `scale` — Factor applied to font data.

## Discussion

This changes outlines, layer metrics, kerning, units per em, and numeric metrics-key offsets.

## See Also

### Copying and Scaling

- [`GSFont copyWithOptions:`](/Core/GlyphsCore/GSFont/copyWithOptions:) — Creates a copy of the font with selected glyph and layer data.
- [GSFont Internal](/Core/GlyphsCore/GSFont-Internal)