---
title: "WindowWidthSizeClass"
description: "Width-based window size class.
A window size class represents a breakpoint that can be used to build responsive layouts. Each
window size class breakpoint represents a majority case for typical device scenarios so your
layouts will work well on most devices and configurations.
For more details see Window size classes documentation."
type: "class"
---
Class
Common
```kotlin
value class WindowWidthSizeClass private constructor(private val value: Int) :
Comparable
```
Width-based window size class.
A window size class represents a breakpoint that can be used to build responsive layouts. Each
window size class breakpoint represents a majority case for typical device scenarios so your
layouts will work well on most devices and configurations.
For more details see Window size classes documentation.
## Companion Object
#### Properties
Common
```kotlin
val Compact = WindowWidthSizeClass(0)
```
Represents the majority of phones in portrait.
Common
```kotlin
val Medium = WindowWidthSizeClass(1)
```
Represents the majority of tablets in portrait and large unfolded inner displays in
portrait.
Common
```kotlin
val Expanded = WindowWidthSizeClass(2)
```
Represents the majority of tablets in landscape and large unfolded inner displays in
landscape.
Common
```kotlin
val DefaultSizeClasses = setOf(Compact, Medium, Expanded)
```
The default set of size classes that includes `Compact`, `Medium`, and `Expanded` size
classes. Should never expand to ensure behavioral consistency.
Common
```kotlin
val AllSizeClasses = AllSizeClassList.toSet()
```
The set of all size classes. It's supposed to be expanded whenever a new size class is
defined. By default `WindowSizeClass.calculateFromSize` will only return size classes in
`DefaultSizeClasses` in order to avoid behavioral changes when new size classes are
added. You can opt in to support all available size classes by doing:
```
WindowSizeClass.calculateFromSize( size = size, density = density, supportedWidthSizeClasses = WindowWidthSizeClass.AllSizeClasses, supportedHeightSizeClasses = WindowHeightSizeClass.AllSizeClasses
)
```