King Single vs Split King vs Super Split King: What’s the Difference?

When I was at the Brisbane Home Show this September, I showcased It-Fits® fitted sheets alongside Better Living Australia, who displayed their premium adjustable beds. We had our products on display, and so many visitors stopped by, relieved to finally find sheets that would actually fit their adjustable beds after nearly giving up.

That’s when the conversations started. As soon as we talked about which size sheets they needed, the same confusion came up again and again: people weren’t sure whether they had a King Single, a Split King, or even a Super Split King. And honestly, I get it — the names sound so similar that it’s easy to mix them up. In this post, I’ll break down the differences and show you how to figure out which bed size you actually have.

Why the confusion is understandable

The names all sound alike, but they describe very different setups. A King Single is one mattress on its own. A Split King is made from two Long Single mattresses placed side by side. And then there’s the Super Split King, sometimes called a Dual Split King or California Split King, which uses two King Single mattresses together.

At the Home Show, I spoke to people who had a certain bed but were calling it by the wrong name. Others weren’t sure at all, which made it hard for them to know what sheets to buy. Once we cleared up the differences, it was much easier for them to understand exactly what they needed. Many were also surprised to see how well jersey fitted sheets stay on adjustable beds — something they hadn’t experienced with other sheets before.

Let’s break down the sizes

What is a King Single?

A King Single is one mattress on its own. It’s wider and longer than a standard single, making it popular for teens, solo adults, or smaller rooms where a double won’t fit.

What is a Split King?

A Split King is made from two Long Single mattresses placed side by side. Each side can move independently on an adjustable bed, giving couples the flexibility to raise or lower their side without disturbing the other.

What is a Super Split King (also called Dual Split King or Cali Split King)?

This setup uses two King Single mattresses side by side. It’s even larger than a Split King and offers extra space for couples who want maximum room while still enjoying the benefits of independent adjustment.

How do you know which bed size you actually have?

Because the names sound so similar, it’s easy to mix them up. The best way to be sure is simply to measure your mattress. A King Single, a Long Single, and a Split King all have different dimensions, and getting it right makes choosing sheets much easier.

To make things simple, we created our Size Finder Quiz. Just grab a measuring tape, pop in your mattress measurements, and the quiz will tell you exactly which size you have and which sheets will fit.

Do you need one fitted sheet or two?

If you have a split system, such as a Split Queen, a Split King, or even a Super Split King, you’ll need to decide whether to use one fitted sheet or two.

Most people choose the two-sheet option, with one fitted sheet on each mattress. This setup is the most popular because it allows both sides to move independently, giving each person full control of their own comfort.

The other option is to use one fitted sheet that covers both mattresses. Some couples prefer this because it eliminates the gap in the middle. Often, they’ll add a mattress protector on top and then one fitted sheet, so the whole bed feels like one piece. Many adjustable beds also let you sync the remotes so both sides move together, making this option practical if you like a seamless sleep surface.

Why jersey fitted sheets are ideal for adjustable beds

Many people think they need special sheets for adjustable beds, like “butterfly sheets,” semi-split sheets, or other unusual designs. While those options exist, they often don’t solve the problem because they can slip, bunch, or feel awkward to use.

Jersey fitted sheets are different. Because the fabric is naturally stretchy, they move with your mattress instead of working against it. That means they stay snugly in place even as the bed bends or lifts. This flexibility is exactly what you want for an adjustable bed.

With jersey sheets, you don’t need straps, clips, or complicated tailoring to keep them on. They stretch, fit, and hold securely, giving you a smooth, comfortable surface every night.

Final thoughts

At the Brisbane Home Show, so many visitors stopped by our stand and were amazed to discover that fitted sheets could finally stay put on adjustable beds. Many had already given up hope after years of trying different sheets, so the surprise of finding a solution that truly worked was a real “wow” moment.

When it came time to place an order, the real challenge became clear: knowing whether they had a King Single, a Split King, or even a Super Split King setup. That’s where the confusion set in.

The good news is that once you know your size, everything else is simple. Our stretchy jersey fitted sheets adapt, stay snug, and don’t need straps or special workarounds. And if you’re still unsure about your size, just measure your mattress and try our handy Size Finder Quiz.

If you have more questions, leave a comment below. I’d love to hear from you and help clear things up.

Warm regards,

Founder of It-Fits®

FAQs

Q1: What’s the difference between a King Single and a Split King bed?

A King Single is one larger single mattress. A Split King is two Long Single mattresses placed side by side to create a king-size setup.

Q2: What is a Super Split King, and how is it different from a Split King?

A Super Split King (also called a California Split King) uses two King Single mattresses side by side. A standard Split King uses two Long Single mattresses. Some retailers use “Dual King” to mean a Split King (two Long Singles), not a Super Split King.

Q3: Do I need one fitted sheet or two for a split setup?

You can use either. Many people prefer two fitted sheets (one per mattress) so each side moves independently. Others link the remotes and use one king fitted sheet over both to reduce the gap in the middle.

Q4: What is a King Single bed?

A King Single is one mattress on its own. It’s wider and longer than a standard single, often used for teens, solo adults, or smaller rooms.

Q5: What is a Split King bed?

A Split King is two Long Single mattresses placed side by side. Each side moves independently on adjustable bases, giving couples flexibility.

Q6: What is a Super Split King bed?

Also called a Dual Split King or Cali Split King, this setup uses two King Single mattresses side by side for maximum space.

Q7: How do I know which bed size I have?

Measure your mattress. King Single, Long Single, and Split King all differ in dimensions. To make it easier, use the It-Fits® Size Finder Quiz. 

Q8: Do I need one fitted sheet or two for a split bed?

Most people use two fitted sheets, one per mattress. Some couples prefer one sheet over both mattresses to avoid a gap, especially if their bed remotes are synced.

Q9: Do I need to size up when buying sheets for an adjustable bed?

No. With woven sheets, people often size up and get a loose fit. Jersey fitted sheets stretch, so you can buy your normal bed size and still get a snug fit.

Q10: Where can I buy fitted sheets for adjustable beds?

The simplest option is online. It-Fits offers Australia’s widest range of jersey fitted sheets for adjustable sizes, including King Single, Split King, and Super Split King.

Q11: Why do jersey fitted sheets work best on adjustable beds?

Jersey fabric stretches with your mattress, so the sheets stay snug and smooth as the bed moves. No straps, clips, or special tailoring are needed.