Karlovo náměstí is a pylon station with 3 supports. The depth of the station is 40 metres and it is 165 metres long, including service rooms. The length of the middle tunnel is the same as the length of platforms. The interior design consists of metal tubing (station tunnels leading to other stations feature concrete design). The facing consists of glass blocks, designed by František Vízner, placed over a beige colour film. Similar designs are used in other stations of the B line. The same blocks, despite their size, were in use on Jinonice station. The transfer corridor walls are faced by CONNEX glass (as in most of the B line stations).