What is the radius of the windows on BigSur? I read Apple's What's New in macOS about BigSur, and they have mentioned about an increase in the window radius, but they have not mentioned anywhere about what the radius is.

Throughout macOS 11, windows adopt visual touches that recall iOS interfaces. For example, windows integrate the sidebar, toolbar, and content areas, use an increased corner radius, and display lightweight controls.

In the past, the windows on macOS had a radius of around 7px. In BigSur, it is very clear that the radius of the corners has increased, but what is the exact radius of the windows?
As far as I can tell from analyzing a screenshot from a MacBook Pro 15 Inch: 18px