✎ Corner Radiuses of iOS Icons at Different Sizes

I still see icons getting this wrong, and there is some misinformation about which numbers to follow. Hicksdesign has the accurate numbers, and they are as follows:

Icon512.png                   512px           89.825

Icon.png                         57px             10

Icon@2x.png                  114px           20

Icon-72.png                   72px             12.632

Icon-72@2x.png            144px            25.263

Icon-Small.png               29px             5.088

Icon-Small@2x.png        58px             10.175

An easy rule of thumb if you want to create a matching inner radius is to subtract the spacing from the outer shape from the corner radius. Ie, if I make a roundrect at 57x57 with 10 px radius (the standard iPhone shape), then make an inner shape that’s 49x49, 4 px from the edges, the matching corner radius would be 6 px (10-4 = 6).