Standard bed sizes are based on standard mattress sizes, which vary from country to country. A king size bed is wider than a queen bed. While a queen size bed is 60 inches (152 cm) wide, a king size bed is 76 inches (193 cm) wide. Both bed sizes are 80 inches (203 cm) long. Then they will have a good idea of what to expect from UK bed sizes US Bed & Mattress.