Tennis courts are flat rectangular playing surfaces used for the sport of tennis. Measuring 78’ (23.77 m) by 36’ (11 m) for doubles or 27’ (8.2 m) for singles, tennis courts have an overall playing area of 2,808 ft2 (260.9 m2). To ensure the safety of the players as they chase balls outside the court boundaries, a clearance space of 21’ (6.4 m) should be provided beyond the baselines and 12’ (3.66 m) for the sides. The total area required for the court and the clear space is 7,200 ft2 (668.9 m2). Tennis courts vary in materials depending on indoor or outdoor uses. Outdoor courts are made of grass, clay, or acrylic topped concrete, and indoor courts are commonly topped with hardwood flooring or carpet.