UK Mattress Size Guide: Dimensions in cm & Feet
Finding the right mattress size is an important first step when choosing a new bed. This guide explains the standard UK mattress dimensions from small single through to super king, with practical points to check before you buy.
Standard UK mattress sizes run from Small Single at 75 × 190 cm through to Super King at 180 × 200 cm. Measure the inside of your bed frame—not the outside—and match the measurements in centimetres before ordering.
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The Essentials
What Really Matters
Standard UK Dimensions
Unlike international standards, UK mattress sizes are specific. Most standard lengths are 190cm, while King and Super King sizes increase to 200cm in length. Understanding these fixed dimensions is essential before buying frames or fitted sheets.
Frame vs Mattress Size
It is a common error to confuse the external dimensions of a bed frame with the internal mattress space. Always measure the bed slats or the interior frame area to confirm your chosen mattress will sit flush without gaps.
Room Proportions
Consider the walk-around space in your bedroom. A Super King is luxurious, but if it prevents you from opening wardrobe doors or makes the room feel cramped, a standard King or Double is often a more practical choice.
Buying Advice
How to Choose the Right Mattress
UK Mattress Size Chart
| UK size | Dimensions (cm) | Approx. dimensions (feet/inches) | |---|---:|---:| | Small Single | 75 × 190 cm | 2'6" × 6'3" | | Single | 90 × 190 cm | 3'0" × 6'3" | | Small Double | 120 × 190 cm | 4'0" × 6'3" | | Double | 135 × 190 cm | 4'6" × 6'3" | | King | 150 × 200 cm | 5'0" × 6'6" | | Super King | 180 × 200 cm | 6'0" × 6'6" |
Quick lookup: 90 × 190 cm = Single; 120 × 190 cm = Small Double; 135 × 190 cm = Double; 150 × 200 cm = King; 180 × 200 cm = Super King. These are standard nominal UK mattress dimensions, so always check the manufacturer's exact measurements before ordering.
How to Tell What Size Mattress You Have
Remove all bedding and measure the mattress itself, not the outside of the bed frame. Measure width from side to side at the widest point, then length from head to foot. Compare those figures with the chart above. Around 90 × 190 cm is a Single, 135 × 190 cm is a Double, 150 × 200 cm is a King and 180 × 200 cm is a Super King. If your measurements sit between standard UK sizes, the mattress may be European, bespoke or another non-standard size. Measuring in centimetres is the safest way to identify it.
How Big Is a Double Mattress in the UK?
A standard UK Double mattress is 135 cm wide and 190 cm long, approximately 4 ft 6 in × 6 ft 3 in. It is 15 cm wider than a Small Double at 120 × 190 cm and 15 cm narrower than a King at 150 × 200 cm. A Double is a common choice for two adults where bedroom space is limited, but a King gives each sleeper more width and adds 10 cm of length.
King Size Mattress Dimensions UK
A standard UK King mattress measures 150 × 200 cm, approximately 5 ft × 6 ft 6 in. Unlike Single, Small Double and Double mattresses, a UK King is normally 200 cm long rather than 190 cm. That extra length can be useful for taller sleepers. Measure the inside of the bed frame before ordering rather than relying only on the label 'King', especially with imported frames.
Super King Size Dimensions
A standard UK Super King mattress measures 180 × 200 cm, approximately 6 ft × 6 ft 6 in. It is 30 cm wider than a UK King while keeping the same 200 cm length. Before buying, check bedroom circulation space, staircase and doorway access as well as the internal dimensions of the bed frame.
Small Double, Single and Small Single Sizes
A Small Single is 75 × 190 cm and a standard Single is 90 × 190 cm. A Small Double—sometimes called a three-quarter bed—is 120 × 190 cm. A Small Double can work well where one person wants more room than a Single but the bedroom cannot comfortably accommodate a standard Double.
UK vs European Mattress Sizes
UK and European mattress sizes are not interchangeable simply because they use similar names. For example, a common European double is 140 × 200 cm, compared with a UK Double at 135 × 190 cm. Always buy by the actual centimetre dimensions when matching a mattress to an existing frame.
How to Measure a Bed Frame for a Mattress
Measure the internal width and internal length of the area where the mattress sits. Do not measure the outside edges of the frame, because headboards, side rails and upholstery can make the bed considerably larger than the mattress. If replacing an existing mattress, measure both the old mattress and the frame opening. For a new room layout, mark the mattress footprint on the floor before buying. If your current mattress is worn or sagging, also read our guide to how often you should replace a mattress before choosing its replacement.
Our Tip
Always check your bedroom door and hallway width before ordering a Super King mattress to ensure it can actually be delivered into the room.
Our Tip
If you are taller than 6ft, we recommend opting for a King or Super King, as these are the only standard sizes that provide a 200cm length.
Quick Checklist
Do's & Don'ts
Do's
- Measure your bedroom floor space with a tape measure.
- Check the path from your front door to the bedroom for narrow turns.
- Measure the internal space of your existing bed frame.
- Consider the height of the mattress as well as length and width.
- Decide if you need extra length for height (King/Super King).
- Check if your current fitted sheets will fit the new size.
Don'ts
- ✕Ignore bed frame thickness
- ✕Assume international sizes are the same
- ✕Forget clearance
Questions
Frequently Asked Questions
The common standard sizes are Small Single 75 × 190 cm, Single 90 × 190 cm, Small Double 120 × 190 cm, Double 135 × 190 cm, King 150 × 200 cm and Super King 180 × 200 cm. Check the exact manufacturer dimensions before ordering.
Measure the mattress edge to edge in centimetres and compare the width and length with a UK mattress size chart. For example, approximately 135 × 190 cm indicates a UK Double, while 150 × 200 cm indicates a UK King.
A standard UK Double mattress is 135 cm wide and 190 cm long, approximately 4 feet 6 inches by 6 feet 3 inches.
A standard UK King mattress measures 150 × 200 cm, approximately 5 feet by 6 feet 6 inches.
A standard UK Super King measures 180 × 200 cm, approximately 6 feet by 6 feet 6 inches.
No. Names can sound similar while the dimensions differ. A common European double is 140 × 200 cm, whereas a UK Double is 135 × 190 cm, so check measurements rather than relying on the size name.
A Small Double is 120 cm wide, giving two people about 60 cm each if shared equally. It can accommodate two adults, but many couples may prefer the additional width of a Double, King or Super King where room space permits.
A UK Small Double mattress measures 120 × 190 cm, approximately 4 feet by 6 feet 3 inches. It is sometimes called a three-quarter bed and is 15 cm narrower than a standard Double.
A UK King mattress is 150 cm wide and 200 cm long. That is 15 cm wider and 10 cm longer than a standard Double, giving each of two sleepers 75 cm of personal space.
A UK King is 150 × 200 cm and a UK Super King is 180 × 200 cm. The Super King gives 30 cm more width but the same length. Both are 200 cm long, which is 10 cm longer than Single, Small Double and Double sizes.
Remove all bedding and measure the sleeping surface from edge to edge in centimetres — width first, then length. Do not measure the depth for sizing purposes, but do note it down as some fitted sheets list depth ranges. Compare your width and length measurements against the UK size chart to identify your size.
Not always. A European Single is typically 90 × 200 cm (10 cm longer than a UK Single), and a European Double is often 140 × 200 cm (5 cm wider and 10 cm longer than a UK Double). Always check the exact dimensions before mixing UK frames with European mattresses or vice versa.
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Evidence
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