Mattress size calculator: what fits your bedroom?
Enter your room size and who sleeps in the bed. The calculator checks every standard UK mattress size against the room, leaving room to walk round it, and tells you the biggest one that fits comfortably.
Our recommendation
Super king
180 × 200 cm · Couples with a child or pet, or light sleepers
It leaves 75 cm spare at the narrowest point, above the 60 cm walkway most people find comfortable.
| Size | Mattress | In your room |
|---|---|---|
| Small single | 75 × 190 cm | Fits comfortably107 cm spare |
| Single | 90 × 190 cm | Fits comfortably100 cm spare |
| Small double | 120 × 190 cm | Fits comfortably100 cm spare |
| Double | 135 × 190 cm | Fits comfortably97 cm spare |
| King | 150 × 200 cm | Fits comfortably90 cm spare |
| Super king | 180 × 200 cm | Fits comfortably75 cm spare |
Picked a size? Compare the mattresses we've scored or see the full UK size chart.
How it works
The bed goes headboard-to-wall, and the calculator tries it both ways round. It needs 60 cm of walkway on each side you get in from and past the foot to call it a comfortable fit. Between 45 and 60 cm is marked as tight. A bed frame adds about 10 cm on each dimension; a divan sits at the mattress size.
The recommendation also takes into account who is sleeping in it: two adults need at least a double, and anyone over 6 ft needs a 200 cm long king or super king.
| Size | Width × length | Best for |
|---|---|---|
| Small single | 75 × 190 cm | Children and bunk beds |
| Single | 90 × 190 cm | One adult or a teenager |
| Small double | 120 × 190 cm | One adult who spreads out; a squeeze for two |
| Double | 135 × 190 cm | Couples, at 67.5 cm each |
| King | 150 × 200 cm | Couples who want room, and anyone over 6 ft |
| Super king | 180 × 200 cm | Couples with a child or pet, or light sleepers |
Frequently asked questions
How much space do you need around a bed?
About 60 cm of walkway on each side you get in from, and past the foot of the bed. That is enough to walk past and make the bed. 45 to 60 cm works but feels tight, and below 45 cm you are climbing in from the end.
Will a king size bed fit in a 3 m by 3 m room?
Yes. A king mattress is 150 × 200 cm; on a frame that adds about 10 cm, it leaves roughly 70 cm either side and 90 cm past the foot, comfortably above the 60 cm guide. A super king (180 × 200 cm) leaves about 55 cm each side, which is a tight fit.
What is the smallest room for a double bed?
A double is 135 × 190 cm. With 60 cm on both sides and at the foot, and 10 cm for the frame, you need a room about 2.65 m wide and 2.6 m long. Push one side against a wall and the width drops to about 2.05 m.
What size mattress do I need if I'm over 6 ft?
Anyone over about 183 cm (6 ft) should look at a king or super king, which are 200 cm long. Single, small double and double mattresses are 190 cm, which leaves almost no room once your pillow is in place.