The Sloom King Mattress: What You Need to Know

Everything you need to know before buying a king mattress or a Cape Town King mattress in South Africa: sizes, prices, what's inside, and how they compare.

A king mattress is the natural upgrade for couples who've outgrown a Queen, or anyone who simply wants more room to stretch out. At 188cm x 182cm, a king mattress gives each side of the bed genuinely independent space, which matters more than it sounds once you're sharing a bed every night. If King still isn't wide enough, the Cape Town King mattress goes even further, and we'll cover exactly how the two compare below.

What's inside a Sloom King Mattress

The Sloom Original Mattress is built from five foam layers: 40mm of ultra-dense memory foam on top, 20mm of high-density transitional foam beneath it, 40mm of cool latex foam, 30mm of high-density comfort foam, and a 120mm high-density support core underneath it all. The whole thing is wrapped in a removable, washable 500gsm zip cover. This construction is the same across every size, from Single up to the Cape Town King.

Firmness, without having to guess

Rather than committing to one feel, the mattress layers are designed to be rearranged into three settings: soft, for a plush, conforming feel that suits side sleepers; medium, a balanced, responsive feel for mixed sleeping positions; and firm, a stable, grounded feel for back and stomach sleepers. On King and Cape Town King, split comfort technology means each side of the bed can be set to a different firmness, so you're not compromising just because you share a bed.

King, King Extra Length, or Cape Town King mattress?

King isn't a single fixed size. Sloom offers three ways to go bigger than Queen, and the difference between them comes down to whether you need more length, more width, or both.

King is the standard option: 188cm long and 182cm wide, enough for two people to sleep without disturbing each other. King Extra Length keeps the same width and adds 12cm of length, worth it if you or your partner are tall and your feet reach the end of a standard king mattress.

The Cape Town King mattress goes further in both directions: 200cm long and 214cm wide, wider than a King and even wider than a California King. It is unique to Sloom, and was created specifically because nothing else on the market was big enough for buyers who wanted the extra length and width. It's currently the largest mattress size available in the country.

How the king mattress compares to every Sloom size

If you're weighing a king mattress against a smaller size, here's the full range for context. Every size is also available in Extra Length (200cm), which adds R1,000 to the price:

The jump from Queen to King adds 30cm of width, the difference that lets two people each have their own space rather than sharing one continuous sleeping surface. Split comfort technology, which lets each side of the mattress be set to a different firmness, is available from Queen upward, so it's not exclusive to King, but it's especially worth using once you're on a king mattress or Cape Town King mattress and genuinely have room for two distinct setups.

Trial, guarantee, and warranty

Every Sloom King Mattress comes with a 100-night risk-free trial, with a full refund available between days 60 and 100 if it's not right for you. It's backed by a 2-year guarantee against faults and a 25-year service warranty, so it's built to be a long-term decision rather than a compromise.

Shop the King Mattress

Completing the king bed

Once the mattress is sorted, a king bed frame, fitted sheet, and duvet cover set in a matching tone finish the room. If you'd rather sort it all in one order, the Ready to Sleep Bundle bundles the mattress, bed frame, sheets, and duvet cover together and includes flexible payment options at checkout. Going Cape Town King instead? The Cape Town King Bundle is sized specifically for it. Not sure which size is right for your room? The mattress size guide walks through how each size compares.

Frequently asked questions about the King Mattress and the Cape Town King

What size is a king mattress in South Africa?

A Sloom king mattress measures 188cm x 182cm and starts at R16,900. A King Extra Length version, 200cm x 182cm, is also available for R17,900.

What is a Cape Town King mattress?

The Cape Town King is a South African mattress size created by Sloom, measuring 200cm x 214cm. It's wider than a standard King and even wider than a California King, and it's currently the largest mattress size sold in the country. It's priced at R23,900.

Is the Cape Town King bigger than King Extra Length?

Yes. King Extra Length adds 12cm of length over a standard king mattress but keeps the same 182cm width. The Cape Town King adds both length (200cm) and significantly more width (214cm), making it the largest option overall.

How much does a king mattress cost?

A Sloom king mattress starts at R16,900. King Extra Length is R17,900, and the Cape Town King is R23,900. All sizes include the same 100-night trial, 2-year guarantee, and 25-year service warranty.

Shop the King Mattress | Shop the Cape Town King Bundle | Read the full mattress size guide