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King Size Mattresses

A king size mattress is one of the largest widely available mattress sizes in the UK. Choose your mattress from a wide range of well-known manufacturers like Silentnight, Rest Assured, Dunlopillo, Sealy, Sleepeezee and many more.

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250 results


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Based on 22,224 reviews

Trustpilot Star rating Verified

Ordered sunday night,delivered monday afternoon.Super comfy mattress.Would use again in a heart beat.

Mark St 18th Apr
Trustpilot Star rating Verified

Good selection of mattress for all size and firmness and price points with option to take old mattress away a little pricey maybe but usefull and a varied delivery time slots to suit. Have used several times and will continue to do so

Gary 18th Apr
Trustpilot Star rating Verified

Sunday delivery was an option which really worked for me and was free, which was a bonus. The communication was really good and they turned up on time. The guys were in and out in 5 mins. The mattress is sooo comfortable and really good value.

Christine 18th Apr

Help & Buying Guides

Why choose a kingsize mattress?

When it comes to mattresses, bigger ones can be better. King size mattresses offer an expansive sleeping surface, measuring 150cm in width and 198cm in length, which is an extra six inches wider and three inches longer than a standard double. 

One of the most often-overlooked considerations is whether or not you have the room. However, as long as there is room at either side for each person to get in and out, there’s no reason to pass up the chance to doze off on a superior sleeping surface.

For those with larger bedrooms, a king size mattress on a king size bed will act as a stunning centrepiece. To add impact and appeal to the aesthetics, crown yours with a well-chosen headboard. These are available in a range of designs, materials, and colours, so you can choose one to suit your surroundings.

Generally speaking, king size mattresses are ideal for those who are a little wider or taller than the average person. The extra length will prevent those with longer legs from exposing their feet to the cold, while the additional width gives plenty of room for your bedfellow.

King size mattresses are also beneficial for those prone to nocturnal wriggling. To minimise motion transfer between sleepers, look for king size mattresses with pocket springs. These are springs individually housed in fabric pockets. Free to move independently, they react to the movement of each sleeper without causing the rest of the mattress to wobble. With the added space, you can shift position throughout the night, and your partner won't feel a thing.

What size is a king size mattress?

All our king size mattresses are 5' x 6' 6" (150 cm x 200 cm). This is both longer and wider than a double mattress, which measures 135cm x 190cm, and comfortably accommodates two sleepers. King size mattresses are incredibly popular in the UK, and they’re especially loved by families with young children who appreciate that bit of extra space for the little ones to climb into in the mornings. In fact, there are only two types of mattresses that are bigger: the super-king mattress, and the emperor.

The depth of a king mattress varies depending on what sort of option you choose. The shallowest choices are around 14cm deep, which are very lightweight and convenient. The thickest options are around 35cm deep, offering a little more comfort for those who like a more robust feel to their king size bed.

King size mattresses work great with our range of King size divan beds.

Find the right king size mattress brand for you:

We stock hundreds of king size mattresses from our extended range of leading mattress brands. Regardless of the brand you choose, you will find the perfect king size mattress at a price you will love. 

Silentnight king size mattresses

Are you a Silentnight fan? If yes, then you’ll love our collection of Silentnight king size mattresses. If you are looking for a new mattress that provides full back care support, then check out our Silentnight Miracoil mattresses. Alternatively, if you looking for a mattress to sink into, browse our Silentnight memory foam mattresses that we have available.

Sealy king size mattresses

A Sealy king size mattress is a perfect choice if you are looking for high-quality comfort. If you need a mattress with great support for your back, our Sealy ortho mattresses will provide a great solution. Furthermore, our Sealy hypoallergenic mattresses are ideal for those suffering from allergies.

Sleepeezee king size mattresses

Our Sleepeezee king size mattress range has something for everyone, suiting all budgets and preferences. Whether you looking for a mattress that provides a healthy spinal alignment, or a model that has natural fillings such as wool, then look no further than our Sleepeezee mattress collection. 

Hypnos king size mattresses

We are delighted to offer a wide range of luxurious Hypnos king size mattresses. Hypnos are renowned for using superior-quality materials that ensure models are eco-friendly and provide premium comfort. Being Royal Warrant holders as well, just shows why Hypnos mattresses are one of the most sought after brands. 

SleepSoul king size mattresses

If you are looking for great value for money and plush comfort, look no further than our SleepSoul king size mattress range. There are memory foam options, hybrid mattress options and even cool gel and reflex foam models available. Plus, with all models being rolled up for delivery, it makes it easier for you to transfer your mattress to the room you want it in.

Emma king size mattresses

We proudly offer an extensive range of Emma king size mattresses, well-known for their pressure-relieving memory foam and innovative zoning. If you're seeking a mattress that can be customized to your preference, the Emma Original mattress is perfect for you. And if you need a breathable mattress for a cool night's sleep, you'll find the Emma Hybrid a fantastic fit.

Simba king size mattresses

For those who crave a sleep experience that combines the benefits of foam and spring, look no further than our Simba king size mattresses. Simba's hybrid mattress range gives you a harmonious blend of supportive pocket springs and responsive memory foam. If you're interested in sleep technology, then the Simba Luxe mattress is your ideal choice with its multiple layers of comfort, providing an unrivaled sleeping experience.

Relyon king size mattresses

 For those seeking luxury, our Relyon king size mattresses offer supreme comfort and exquisite craftsmanship. Relyon mattresses are known for their durable and supportive pocket springs, along with their luxurious natural fillings. Whether you're after a firm orthopedic mattress or a softer, plush sleep surface, Relyon has a mattress that can meet your needs. All Relyon mattresses are handcrafted in the UK, ensuring the highest standards of quality

Choose your perfect king size mattress by type:

There are many different options available when it comes to a king size 5ft mattress, allowing you to select your preferred firmness, material, and spring count. King size mattresses are available in a soft to extra firm feel and with spring counts ranging from 800-1200 to more than 4000. In terms of material, there’s a wealth of choice, with everything from pocket and Miracoil springs to natural fillings, memory foam, gel foam, and even medical grade options. Our most popular options of 5ft mattresses include pocket sprung and memory foam.

Pocket sprung king size mattresses

A pocket sprung king size mattress features individual springs which are wrapped up in their own cloth sleeve. This allows the mattress to be responsive to movements throughout the night. These designs are usually available in a medium to firm king size mattress, which can help promote good posture while providing a comfortable night’s sleep.

If you sleep on your back, then you will need a higher level of support to ensure your spine is correctly aligned. For the best support, we recommend pocket sprung mattresses. We advocate a firm or medium-firm king size mattress.

Memory foam king size mattresses

A king size memory foam mattress is made from a special foam material that moulds to the body’s contours as you change sleeping position. These mattresses are especially popular amongst people who suffer from back pain, as they provide a good level of support and cushion your joints.

A king size memory foam mattress is perfect for side sleepers, as you'll benefit from a mattress that provides a lot of cushioning, especially if you have wide hips or shoulders. A medium or softer king size mattress would be ideal.

Hybrid king size mattresses

Also called a combination mattress, a hybrid king size mattress combines foam comfort with supportive pocket spring layers. As a result, you'll have great back support and maximum comfort.

Hybrid king size mattresses are ideal for those who sleep on their front. For pressure relief, it's important that front sleepers find a good balance between comfort and support. Hybrid mattresses with pocket springs are the most comfortable in this situation, as front sleepers need some cushioning, but less than a side sleeper would.

Orthopaedic king size mattresses

We offer an array of orthopaedic king size mattresses that enhance back support. These types of mattresses are also called ortho mattresses and are considerably firmer than standard models. Perfect if you tend to sleep on your back, an orthopaedic king size mattress will ensure your spine is aligned.

Octaspring king size mattresses

Dormeo developed the Octaspring to create a cooler, fresher feel but with the same responsive feel of memory foam. Octasprings allow up to eight times more airflow, creating a fresher feel that’s great for anyone who suffers from night sweats. The firmness rating sits in the medium range, making them suitable for most sleepers. 

Latex king size mattresses

If you like the feel of memory foam but want something a little greener, natural fibres is the right choice. Latex king size mattresses are not only hypoallergenic and anti-bacterial, but they are also more biodegradable at the end of their life. They’re a friendlier choice if you want to keep your carbon footprint down.

Pillow top king size mattresses

A combination of firm support but that deliciously soft, sinking-into-bed feel at the end of a busy day, a pillow-top king size mattress gives you all the comfort you could need. The softer feel is ideal if you prefer to sleep on your front or side. They’re also usually single-sided so they’re easier to maintain.

Still need help deciding the best king size mattress for your home? Discover the perfect one for you, using our handy mattress guide

How much is a 5ft mattress?

Although a king size bed mattress is the ultimate in luxury, it is a lot more affordable than many people think. Most of our mattresses at this size cost between £200 and £700. However, prices for a cheap king size mattress start at less than £120, and our more luxurious mattress options range from £1500 - £5000. We guarantee that we offer some of the best prices in the UK and we really do have something to suit all budgets. And, don't forget, we also offer free next day delivery across the mainland of UK. 

Size Imperial Metric
Cot Mattress 3'9" x 1'9" 120cm x 60cm
Cot Bed Mattress 4'6" x 2'3" 140cm x 70cm
Adjustable Small Single 2'6" x 6'6" 75cm x 200cm
Adjustable Single 3' x 6'6" 90cm x 200cm
Adjustable Small Double 4' x 6'6" 120cm x 200cm
Adjustable Double 4'6" x 6'6" 135cm x 200cm
Small Single 2'6" x 6'3" 75cm x 190cm
Single 3' x 6'3" 90cm x 190cm
Small Double 4' x 6'3" 120cm x 190cm
Double 4'6" x 6'3" 135cm x 190cm
King Size 5' x 6'6" 150cm x 200cm
Super King 6' x 6'6" 180cm x 200cm
European Small Single 2'8" x 6'6" 80cm x 200cm
European Single 3' x 6'6" 90cm x 200cm
European Double 4'7" x 6'6" 140cm x 200cm
European King Size 5'3" x 6'6" 160cm x 200cm

All mattress sizes given are approximate and stated sizes refer to the sleeping surface only. Mattresses sizes may vary slightly from their stated dimensions due to manufacturing tolerances, please allow +/- 2 inches (5cm).

Support Best for
 Icon for Memory Foam Memory Foam Body moulding and pressure relieving
 Icon for Natural Fibres Natural Fibres Unrivalled comfort, naturally temperature-regulating
 Icon for Latex Latex Breathable, supportive and eco friendly
 Icon for Cool Gel Memory Foam Cool Gel Memory Foam Active cooling properties, ideal for hot sleepers
 Icon for Soft White Fibres Soft White Fibres Hypoallergenic polyester, soft and durable

Support Best for
 Icon for Pocket Springs Pocket Springs Individual springs for tailored support
 Icon for Foam Foam Conforms to your body's shape, silent (no springs)
 Icon for Open Coil Springs Open Coil Springs Traditional, interlinked springs
 Icon for Pocket Springs Latex Bouncy yet supportive, great for hot sleepers

Firmness Best for
Good for side sleepers, a softer level of support
Good all-rounder for front, side or back sleepers
Medium - Firm
Good for people who change sleeping position
Good for people who sleep on their front or back
Extra Firm
The firmest level of support, also known as orthopaedic