The iPhone 5s has a 4in display, which is beginning to look very small when held side-by-side with big-screen Android devices. The 16: 9 aspect ratio means it’s tall but thin, so your thumb can comfortably reach from the bottom left corner all the way up to the top right. The bezels at either side are a rather slim 4mm thick, meaning 60.6% of the entire front surface is comprised of screen.