King Size Mattresses (5ft)

Why choose a king size mattress?

A king size mattress gives you more width and length than a standard double, while still fitting many main bedrooms more easily than a super king. It is one of the most popular choices for couples because both sleepers have more personal space to settle comfortably. The standard UK king size is 150cm x 200cm, or 5ft x 6ft 6in. That extra length can be useful for taller sleepers, while the additional width gives couples more room than a 135cm x 190cm double mattress. A king size mattress can offer:

• A 150cm x 200cm sleeping surface for more space than a double bed

• A practical upgrade for couples sharing a main bedroom, without taking up too much room

• Extra length for taller sleepers compared with a standard double

• A wide choice of pocket sprung, memory foam and hybrid designs, as well as mattresses with natural fillings

• Different firmness levels, from soft through to extra firm

• More space to use the mattress edges comfortably when sharing

How to choose the right king size mattress

Start with how the mattress needs to feel. A king size mattress gives you more space, but the right choice still depends on firmness, comfort layers, support system and how the mattress responds when you move. If you share your bed, think about both sleepers. Look for a king size mattress that feels comfortable across the whole surface, limits movement between sleepers and provides good support around the edges, so neither person feels pushed into the middle.

Firmness and comfort

Firmness describes how soft or supportive the mattress feels. Comfort layers shape the cushioning at the surface. Use the table below as a general guide, then check the individual product details before ordering.

Mattress type and construction

Construction affects how a king size mattress responds, supports and regulates temperature. Pocket springs can help the mattress respond independently to each sleeper, while memory foam creates a closer, more cushioned feel. Hybrid designs combine spring support with comfort layers, and natural fillings can appeal if breathability and material choice are priorities. Compare mattress type alongside firmness, depth and comfort fillings rather than choosing on one feature alone. Two king size mattresses can share the same firmness rating but feel different because the internal construction is not the same.

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Buying guidance for king size mattresses

What size is a UK king size mattress?

A standard UK king size mattress measures 150cm x 200cm, or 5ft x 6ft 6in. This makes it 15cm wider and 10cm longer than a standard double mattress, while still being 30cm narrower than a super king mattress.

Always check your bed frame before ordering. Some European or imported frames use different sizing, so measure the inside of the frame rather than relying on the name alone.

Will a king size mattress fit your room?

A 5ft mattress gives you more sleeping space, but you still need enough room around the bed for everyday use. Before buying, measure both the bedroom and the route to the bedroom, particularly if the mattress is deep, heavy or delivered flat rather than rolled. Before ordering, check:

• The full 150cm x 200cm mattress footprint and the size of your bed frame

• Space to walk around the bed and open wardrobes, drawers and doors

• Bedroom doorways, hallway corners, stairs and landings

• Lift dimensions if the mattress is going to an apartment

• Whether the mattress arrives rolled or flat on the individual product page

• Mattress depth, if you need extra-deep fitted sheets or a lower finished bed height

Rolled king size mattresses can be easier to move through tighter spaces, but they still need room to expand once unpacked. Traditional flat mattresses may need more careful access planning, especially in older homes with narrow staircases.

Choosing a king size mattress for two

A king size mattress is a popular choice for couples because it gives both sleepers more room than a double. Each person gets around 75cm of width, which can make the bed feel more settled if you move around or prefer different sleeping positions.

If you share your bed, pay particular attention to motion isolation and edge support. Motion isolation helps reduce movement travelling across the mattress when one person turns over or gets up. Edge support can make more of the mattress feel usable, which is useful when two people sleep close to the sides. Couples may want to compare:

• Pocket sprung or hybrid designs, where springs move independently

• Memory foam or substantial comfort layers that can help soften movement

• Reinforced edges, if you want the full width of the mattress to feel stable

• Medium firm or split-firmness options if two sleepers prefer different support levels

• Zip and link king size mattresses, where available, for more flexible access or firmness choices

Comfort is personal, so a mattress that suits one couple may not suit another. Compare the support system, comfort fillings and firmness rating together, then check product reviews and specifications before ordering.

Which king size material should you choose?

The right material depends on how you like your mattress to feel and what matters most when you sleep. Some people prefer the responsive feel of springs, while others like closer cushioning from foam or the breathable feel of natural fillings.

Construction is only one part of the decision. Firmness, depth, comfort layers, your bed base and your body weight can all influence how a king size mattress feels in practice. For help choosing the right mattress for you, check out our comprehensive mattress buying guide.

Looking after your king size mattress

Read the care instructions supplied with your mattress before turning or rotating it. Some king size mattresses are single-sided, while others may need regular turning, so it is always best to follow the guidance for the model you choose. If your mattress has handles, use them for positioning rather than carrying the full weight of the mattress. A king size mattress can be heavy and awkward to move, so two people may be needed for safe handling. Using a suitable king size bed base and a mattress protector can also help keep your mattress in better condition. Warranty or guarantee terms vary by product, so check the individual product page and manufacturer guidance before ordering.

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