# convert(_:from:) Converts a size from another view’s coordinate system to that of the view. ``` func convert(_ size: NSSize, from view: NSView?) -> NSSize ``` ## Parameters `size` The size (width and height) in view’s coordinate system. `view` The view with `size` in its coordinate system. Both `view` and the view must belong to the same [`NSWindow`](/documentation/AppKit/NSWindow) object, and that window must not be `nil`. If `view` is `nil`, this method converts from window coordinates instead. ## Return Value The converted size, as an structure. ## Discussion The returned `NSSize` values are always forced to have positive a width and height. You can also use this method to get a view’s current magnification or zoom level, if it’s been changed from the default scale. Specifically, if you convert a known size from the window’s base coordinate space to that of `view`, the result is the current zoom level. ## See Also [`contentView`](/documentation/AppKit/NSWindow/contentView) The window’s content view, the highest accessible view object in the window’s view hierarchy. [`ancestorShared(with:)`](/documentation/AppKit/NSView/ancestorShared(with:)) Returns the closest ancestor shared by the view and another specified view. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)