---
title: "sizeThatFits(_:)"
framework: swiftui
role: symbol
role_heading: Instance Method
path: "swiftui/windowlayoutroot/sizethatfits(_:)"
---

# sizeThatFits(_:)

Asks the window’s content for its size.

## Declaration

```swift
func sizeThatFits(_ proposal: ProposedViewSize) -> CGSize
```

## Parameters

- `proposal`: A proposed size for the subview. In SwiftUI, views choose their own size, but can take a size proposal from their parent view into account when doing so.

## Return Value

Return Value The size that the content chooses for itself, given the proposal from its container view.