A king-size mattress is a large bed designed to provide ample sleeping space for individuals or couples. It typically measures 76 inches wide by 80 inches long, making it one of the largest standard mattress sizes available. This extra space allows for comfortable movement during sleep and is ideal for those who prefer more room. King-size mattresses come in various types, including memory foam, innerspring, and latex. They are often paired with matching king-size bed frames and bedding to ensure a cohesive look in the bedroom. Due to their size, they are best suited for larger bedrooms that can accommodate the dimensions.