---
title: itemSize
framework: appkit
role: symbol
role_heading: Instance Property
path: appkit/nscollectionviewflowlayout/itemsize
---

# itemSize

The default size to use for items.

## Declaration

```swift
var itemSize: NSSize { get set }
```

## Discussion

Discussion This property contains the default size of items. If you do not provide an estimated size or implement the collectionView(_:layout:sizeForItemAt:) method in your delegate, the flow layout uses this value for the size of each item. All items are set to the same size. This value applies only to items and not to supplementary views. The default value of this property is (50.0, 50.0). For more information about how item sizes are determined, see Understanding How the Flow Layout is Generated.

## See Also

### Configuring the Item Spacing

- [minimumLineSpacing](appkit/nscollectionviewflowlayout/minimumlinespacing.md)
- [minimumInteritemSpacing](appkit/nscollectionviewflowlayout/minimuminteritemspacing.md)
- [estimatedItemSize](appkit/nscollectionviewflowlayout/estimateditemsize.md)
- [sectionInset](appkit/nscollectionviewflowlayout/sectioninset.md)