A king size mattress is a large bed designed to provide ample space for couples or individuals who enjoy extra room while sleeping. It typically measures 76 inches wide by 80 inches long, making it one of the largest standard mattress sizes available. This size is ideal for those who want to minimize disturbances from movement during the night. King size mattresses come in various types, including memory foam, innerspring, and latex. They are often paired with a matching king size bed frame to support the mattress properly. Many people choose this size for its comfort and ability to accommodate multiple sleepers or pets.