King Size Mattresses - 5ft Mattresses

Our king size mattresses measure 5ft wide and 6ft 6 inches long or 150cm by 200cm. King size mattresses are considerably larger than our double mattresses, making them ideal for couples who like to sprawl out in the bed or just like to get their own space when sleeping. From memory foam to pocket sprung, we offer a variety of 5ft king size mattresses to suit your preferences. Browse the full range of 5ft mattresses below.

73 products

Duke Ortho Mattress – King
Original price was: £318.Current price is: £254.40.
Duke Comfort Mattress – King
Original price was: £318.Current price is: £254.40.
Pearl Mattress – King
Original price was: £1140.Current price is: £342.
Order Now and Get by March 14, 2026
Midnight Mattress – Double
Original price was: £948.Current price is: £379.20.
Ivory Mattress – King
Original price was: £1320.Current price is: £396.
Order Now and Get by March 14, 2026
Midnight Mattress – King
Original price was: £1140.Current price is: £456.

What size is a king size mattress?

A king size mattress measures 5 feet wide (150cm) and 6ft 6 inches long (200cm), making it 6 inches wider and 3 inches longer than a regular double mattress. They are ideal for bedrooms with large floor spaces. The king size mattress comes in a variety of depths depending on the comfort level you choose and whether you opt for a pocket sprung, memory foam or hybrid mattress.

Can a king size mattress fit on a double bed?

While a king size mattress can technically fit on top of a double bed frame, we strongly advise against it. The king size mattress is both longer and wider than a double bed frame, so the mattress will stick over the edge and will be unstable to sleep on. If you need a matching bed frame, we have a variety of king size frames and king size divan sets available.

What is a good king size mattress?

A good king size mattress is one that provides long lasting comfort and a good night’s sleep. This will be different for many people, depending on their preferences, body type and any health conditions.

Pocket sprung king size mattresses – Ideal for those who often wake up with an aching neck or back, pocket springs shape themselves around your body for maximum support. We offer pocket sprung mattresses with anywhere between 1,000 and 35,000 pocket springs.

Memory foam king size mattresses – If you want your mattress to mould to the contours of your body, our memory foam king size mattresses do just that, returning to their original shape when you get off the bed.

Hybrid king size mattresses – Why not get the best of both worlds with a hybrid king size mattress which utilises memory foam technology to remember the shape of your body and pocket springs to provide ultimate support.

You’ll also want to consider how firm you need your mattress. We offer firmness gradings from 1 (soft) to 5 (extra firm) so that you can find the perfect king size mattress for you.

Shopping Basket

Duke Ortho Mattress – King

Duke Comfort Mattress – King

Pearl Mattress – King

Midnight Mattress – Double

Ivory Mattress – King

Midnight Mattress – King

Snooze Easy Mattress – King

Classic Essential 1000 Mattress – King

Cosy Siesta Mattress – King

Classic Pocket 1000 Mattress – King

Zircon Mattress – King

Classic Cool 1000 Mattress – King

Classic Cashmere 1000 Mattress – King

Snooze Rest Mattress – King

Snooze Calm Mattress – King

Burley Mattress – King

Rosaline Mattress – King

Amber Mattress – King

Amatrix Mattress – King

Ebony Natural Mattress – King

Jet Memory Mattress – King

Nova Balance Mattress – King

Emerald Mattress – King

Nova Comfort Mattress – King

Nova Soothe Mattress – King

Deluxe Comfort Mattress – King

Gel Essence Comfort Mattress – King

What size is a king size mattress?

Are all king mattresses the same size?

Can a king size mattress fit on a double bed?

What is a good king size mattress?

Buy 5ft mattresses and more with Sussex Beds