In general, a TV unit should be wider than the width of your television. The catch is that TVs are sold in diagonal inches, making buying the right size TV unit a little bit more complicated. We’ve compiled a list of minimum TV unit lengths alongside common TV sizes. 35 to 45 inch TV = 75cm TV unit 45 to 50 inch TV = 85cm TV unit 50 to 55 inch TV = 100cm TV unit 55 to 65 inch TV = 160cm TV unit 70 inch TV = 180cm TV unit