Which length of Philips HDMI cable I should buy? Updated on 2017-02-28 Measure the distance between your components. This distance should include any additional length that is needed to route the cable around other devices, shelves, or corners. Then add an additional 3 inches on each end, totaling 6 inches. Example calculation: 3 inches + distance from component to component + 3 inches = Ideal suggested length.