Bed Size Guide: Every Standard Mattress Dimension

Buying the wrong size mattress is an expensive mistake — and sizing terminology varies by country in ways that aren’t obvious. A UK “King” is smaller than a US “King.” An EU “Double” uses different dimensions than either. Here is every size, in every unit, with minimum room requirements.

US Mattress Sizes

Size

Inches (W × L)

cm

Who it fits

Twin

38“ × 75“

96.5 × 190.5

1 child or small adult; kids’ rooms, bunks

Twin XL

38“ × 80“

96.5 × 203.2

1 adult, taller sleepers; college dorms

Full / Double

54“ × 75“

137.2 × 190.5

1 adult comfortably, 2 adults tight; guest rooms

Full XL

54“ × 80“

137.2 × 203.2

Full width with extra length

Queen

60“ × 80“

152.4 × 203.2

2 adults; most popular US size

King

76“ × 80“

193.0 × 203.2

2 adults with room; needs large bedroom

California King

72“ × 84“

182.9 × 213.4

Narrower, longer than King — tall sleepers

Split King

76“ × 80“

193.0 × 203.2

2× Twin XL; adjustable base compatible

UK Mattress Sizes

Size

cm (W × L)

Inches

Notes

Small Single

75 × 190

29.5“ × 74.8“

2’6“ — child or box room

Single

90 × 190

35.4“ × 74.8“

3’0“ — standard single

Small Double

120 × 190

47.2“ × 74.8“

4’0“ — cosy double

Double

135 × 190

53.1“ × 74.8“

4’6“ — standard UK couple’s bed

King

150 × 200

59.1“ × 78.7“

5’0“ — standard UK king

Super King

180 × 200

70.9“ × 78.7“

6’0“ — largest standard UK size

European Mattress Sizes

Size

cm (W × L)

Inches

Notes

EU Single

90 × 200

35.4“ × 78.7“

Germany, Scandinavia standard single — 10cm longer than UK

EU Double

140 × 200

55.1“ × 78.7“

Continental standard double

EU Queen

160 × 200

63.0“ × 78.7“

Common in Germany and France

EU King

180 × 200

70.9“ × 78.7“

Same width as UK Super King but equal length

EU Super King

200 × 200

78.7“ × 78.7“

Square format — popular in Scandinavia

Key Differences to Know

UK Double vs US Full: UK Double (135 × 190 cm) is slightly narrower and shorter than US Full (137 × 190 cm). They’re close, but bedding doesn’t always interchange.

UK King vs US King: UK King is 150 × 200 cm (59“ × 79“). US King is 193 × 203 cm (76“ × 80“). These are completely different sizes — a US King is 43 cm wider. Never assume “King” means the same size internationally.

EU vs UK lengths: EU beds are typically 200 cm long; UK beds are 190 cm long. A 6-foot person (183 cm) fits in a UK bed but has 7 cm of margin. An EU bed gives 17 cm of margin.

California King vs Standard King: Same area, different shape. Cal King is 4“ narrower and 4“ longer. Choose Cal King if you are taller than 6’2“ and your bedroom is proportionally shaped; choose standard King if you want maximum width and sleep with a partner who sprawls.

Minimum Room Sizes

The general rule: 24“ (61 cm) clearance on each walking side, 18–30“ at the foot of the bed. These are not comfort suggestions — they’re the minimum needed to walk around the bed to make it and get dressed.

Mattress size

Minimum room

Comfortable room

Twin (38×75“)

7′ × 10′

9′ × 12′

Full (54×75“)

9′ × 10′

10′ × 12′

Queen (60×80“)

10′ × 11′

12′ × 14′

King (76×80“)

12′ × 11′

14′ × 16′

Cal King (72×84“)

11′ × 12′

13′ × 16′

The room fit calculator on this page lets you enter your exact room dimensions and tells you which sizes fit — in any direction — with your chosen clearance amount.

Frame Size: Add 2–5 Inches

Mattress dimensions describe the mattress only. A bed frame adds roughly 2–3“ to each side, depending on style. A platform frame adds less; a traditional frame with rails adds more. When measuring a room, use the mattress dimensions plus 6“ total width and 6“ total length as a frame estimate, then add your clearance on top.

Frequently Asked Questions

I'm moving to Europe from the US — will my King mattress fit?

No. A US King is 193 × 203 cm, but a EU King is only 180 × 200 cm — your mattress is 13 cm wider and won't fit standard EU bed frames. If you're relocating, you'll need to purchase a new mattress that matches your destination country's standard sizes, as bed frames are built to those specific dimensions.

What's the difference between a UK Double and a US Full?

A UK Double is 135 × 190 cm while a US Full is 137.2 × 190 cm — only 2 cm narrower, but the shapes are different enough that bedding (sheets, duvets) often won't interchange properly between the two. If you're buying a UK Double mattress but have US Full bedding, you'll likely need new linens.

I'm 6'4" and considering between a California King and a standard US King — which fits better?

Choose the California King. While both are the same area, a Cal King is 213.4 cm long versus a standard King's 203.2 cm — that extra 10 cm gives you crucial legroom for your height. A standard King's 80-inch length (203 cm) leaves less than 10 cm of space for someone 193 cm tall, which creates discomfort.

Why does the guide mention room requirements if it's just about mattress dimensions?

Room requirements determine whether a mattress will actually fit in your space with usable clearance around the bed. For example, a US King (193 × 203 cm) needs a much larger bedroom than a Queen (152 × 203 cm) — knowing just the mattress size isn't enough; you need to verify your room can accommodate it plus walking space and furniture.