A king size bed measures 150cm wide by 200cm long (5ft × 6ft6) in the UK. It is 15cm wider and 10cm longer than a double, which makes it the most popular upgrade for couples — and the extra length matters if anyone in the bed is over six feet tall.
Table of contents
- King size dimensions
- Room size needed
- King vs double: is it worth upgrading?
- UK king vs US king — they are not the same
- Frequently asked questions
King size dimensions
| Measurement | King size |
|---|---|
| Mattress width | 150cm (5ft) |
| Mattress length | 200cm (6ft6) |
| Typical frame footprint | approx. 165 × 215cm |
| Width per person (couple) | 75cm each |
| Duvet size | 225 × 220cm |
What room size do you need for a king bed?
Allowing the standard 60cm walkway on both open sides and at the foot, a king bed suits a room of at least 2.85m × 2.75m. Many UK double bedrooms hit that comfortably — but check door swings and wardrobe openings before assuming, using our measuring guide.
King vs double: is it worth upgrading?
A double gives each person 67.5cm of width — narrower than a single bed each. A king gives 75cm each plus 10cm more length. For couples, that is usually the single most noticeable comfort upgrade available, and it costs far less than a bigger house. Full comparison: best bed size for couples.
Choose a double instead if your room is under about 2.7m wide on the bed wall, or if you need space for bedside furniture on both sides.
UK king vs US king — they are not the same
A US king is 193 × 203cm — considerably wider than a UK king (150 × 200cm) and closer to our super king. Never buy a mattress or fitted sheet in a different country's sizing standard: it will not fit.
King size ottoman beds — storage included
Handcrafted king frames with full gas-lift storage under the mattress. From £269.99, free UK delivery.
Browse king ottoman beds →Frequently asked questions
What size is a king bed in feet?
Is a king bed big enough for two adults?
What duvet fits a king bed?
Is a UK king the same as a US king?
Compare every size in our UK bed and mattress sizes guide, or see the super king dimensions if you have the space.
