Compare mattress sizes and find the best fit for your room.
Two independent tests decide a mattress size. The first is width per sleeper: a queen at 60 inches gives two adults 30 inches each, which is narrower than a standard single bed and is why couples who move in their sleep prefer a king's 38 inches each. The second is length, which needs to exceed the tallest sleeper's height by about 6 inches so heels and pillows both fit — that rules out 75 inch mattresses for anyone over about 5 ft 9. Room clearance is the third constraint: at least 2 ft each side to walk and make the bed, and enough at the foot to open a wardrobe. A king that passes the comfort test and fails the room test is still the wrong bed.
Mattress Size Fit
Width per sleeper = mattress width / sleepers; side clearance = (room width in inches - mattress width) / 24; length needed = tallest sleeper height + 6 in
It gives each person 30 inches, the same as a standard single. It works for many couples, but if either of you is a restless sleeper a king's 38 inches each is a genuine improvement.
At least six inches longer than the tallest sleeper. Anyone over 5 ft 9 should skip the 75 inch sizes and choose Twin XL, Queen or King, which are all 80 inches.