King or super king? The honest answer for couples, room by room
Most couples sleep on a double because that is what the last flat had. Most couples who move to a king say they should have done it years ago. The question is then whether to go the extra step to a super king, and that is decided by the room more than by the sleepers.
The sizes
| Size | Dimensions | Width per person | Compared with a double |
|---|---|---|---|
| Double (4ft 6) | 135 × 190 cm | 67 cm each: less than a cot mattress | |
| King (5ft) | 150 × 200 cm | 75 cm each | 15 cm wider, 10 cm longer |
| Super king (6ft) | 180 × 200 cm | 90 cm each: a full single each | 45 cm wider, 10 cm longer |
Note the length: king and super king are 200 cm, double is 190. Anyone over about 6ft will feel the extra 10 cm more than the width.
What the width does
- Movement. The single biggest cause of disturbed sleep for couples is the other person moving. Width is the cheapest fix: at 90 cm each, most movement simply does not reach you.
- Temperature. Two people generate heat. Space between you lets it go.
- Different duvets. A super king takes two single duvets side by side with no compromise; a king just about does.
- Children and dogs. If anyone else ever gets in, a super king is the only size where it still works.
What the room decides
A bed needs a walkway of at least 60 cm on each side you get in from, and space for bedside tables if you want them.
| Room width (bed against the head wall) | Fits |
|---|---|
| Under 2.8 m | Double; a king without bedside tables |
| 2.8 to 3.2 m | King with bedside tables |
| 3.2 m and over | Super king with bedside tables |
Length matters too: a 200 cm bed plus a footboard plus a walkway needs a room over about 3.3 m deep. Tape the size out on the floor before deciding; a super king in a 3 m room fits and makes the room a bed.
The practical costs of a super king
- Stairs. A 180 × 200 mattress with a steel edge does not bend. Winder staircases and loft conversions are the problem; see will it fit up the stairs. Zip-and-link (two singles zipped together) solves it.
- Bedding. Super king sheets and duvets cost more and are sold in fewer shops. A super king duvet is enormous to wash.
- The bed frame. Needs a centre support rail and, ideally, a fifth leg; cheap super king frames flex in the middle.
- Moving house. It is the item removal firms swear at.
Split tension
King and super king are the sizes where a mattress can be built with a different tension on each side, one spring unit per side under one comfort layer, with no seam on top. If one of you is much heavier, or wants it firmer, this is the answer, and it is another argument for going up from a double. See split tension explained.
The honest recommendation
- The room is under 2.8 m wide: double, and make it a good one.
- Between 2.8 and 3.2 m: king. This is most couples in most British bedrooms, and it is the right answer.
- Over 3.2 m, a straight staircase, and you are staying: super king. You will not go back.
How we build for it
The Single Life and The Rebound come in king; The Rebound, The New Parent, The Bad Back Years, The Hot Flush and The Hotel Bed in super king. Split tension is available on The Bad Back Years and The Hotel Bed in both. All delivered flat by two people who will tell you in advance if the stairs are a problem.
The short version
- Double gives each of you less than a cot's width. King is the answer for most rooms; super king if the room is over about 3.2 m wide.
- Width fixes movement and heat more cheaply than any material.
- Super king costs you stairs, bedding and a stronger frame.
- King and up unlock split tension for couples who differ.
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