Mattress Dimensions: Picking the Right Size for Your Bed

If you’re shopping for a new mattress, the first question is always the same – what size do I need? Getting the dimensions right can mean the difference between a comfy night’s sleep and a cramped, restless one. In this guide we’ll break down the standard mattress sizes used in the UK, show you how to measure your bedroom, and give practical tips for choosing the best fit.

Standard UK Mattress Sizes

Most retailers stick to a handful of sizes that are easy to recognise. Here’s the quick reference list:

• Single – 90 cm × 190 cm
• Double – 135 cm × 190 cm
• King – 150 cm × 200 cm
• Super King – 180 cm × 200 cm

Those numbers are the width first, then the length. If you’re buying a mattress for a kids’ room, a twin (or “small single”) at 80 cm × 190 cm is also common.

How to Measure Your Space

Before you click “add to cart”, grab a tape measure and follow these steps:

1. Measure the width of the space between the bedroom walls. Note any baseboards or skirting that could eat up a couple of centimetres.
2. Measure the length from the headboard wall to the footboard wall. Remember to leave a little wiggle room for bedding and movement – about 5 cm is a good rule of thumb.
3. Check the height of the room’s ceiling if you plan a high‑profile mattress or a lofted bed.
4. If you’re putting the mattress on a platform or box spring, add its height to the total.

Write those numbers down and compare them to the standard sizes above. The goal is to find a mattress that fits comfortably without bumping into doors or wardrobes.

One quick tip: if you’re between sizes – say you have room for a 155 cm wide bed – a King (150 cm) will fit with a small gap, while a Super King (180 cm) will be too big. You can fill the gap with a custom mattress topper or a narrow side table.

Another thing to think about is the mattress thickness. Most standard mattresses range from 20 cm to 30 cm. If you have low ceilings, a thinner mattress can save you a few centimetres of headroom.

Now that you know the numbers, let’s talk about real‑world considerations.

Practical Tips for Choosing the Right Size

Sleep partners. If you share the bed, add at least 15 cm per person to the width. That’s why couples usually go for a King or Super King – it gives each person enough room to move.

Room layout. Think about where the nightstand, lamp, and any extra furniture will go. A mattress that leaves at least 60 cm of clearance on each side makes it easy to walk around.

Future needs. If you plan to add a child’s bed later or expect a partner to move in, consider buying a size that will accommodate those changes.

Delivery and handling. Bigger mattresses need a bigger door and sometimes a stair lift. Check your entry points before ordering a Super King – you don’t want it stuck in the hallway.

Finally, don’t forget the mattress protector and fitted sheet sizes. They’re made to match the exact dimensions of the mattress, so buying the right size sheet is just as important as the mattress itself.

With these basics in mind, you can walk into any store or browse online with confidence. Measure, compare, and think about how you’ll use the space – and you’ll land on a mattress that feels just right.

Happy sleeping!