How to measure a mattress

If you’re buying a new mattress, it’s important you know how to accurately measure your current mattress and the available space you have around it. Whether it’s for your everday bed at home, a caravan, or even a boat, this guide will explain how to measure your mattress so you can get the best-fitting mattress for the best night’s sleep.

Standard mattress size guide

In addition to choosing the right mattress comfort level, choosing the right size bed and mattress is an important decision to make when refurbing your bedroom. The right size bed and mattress for your needs are crucial for a good night’s rest and optimum comfort.

Standard UK bed and mattress sizes range from cot size to super king with everything in between. If you are buying a new mattress, you should familiarise yourself with the measurement to ensure your new bed and mattress fit:


Dimensions (CM)

Dimensions (FT)

Cot Size
60cm x 120cm
1FT11½ x 3FT11¼
Toddler Size
70cm x 140cm
4FT7 x 2FT3½
Small Single
75cm x 190cm
2FT6 x 6FT3
91cm x 190cm
3FT x 6FT3
European Single
91cm x 200cm
3FT x 6FT6
Small Double
122cm x 190cm
4FT x 6FT3
137cm x 190cm
4FT6 x 6FT3
European Double
140cm x 200cm
4FT7 x 6FT6¾
King Size
152cm x 198cm
5FT x 6FT6
European King Size
160cm x 200cm
5FT3 x 6FT6¾
Super King Size
183cm x 198cm
6FT x 6FT6

NOTE: Measurements provided in the table above are offered as guide only. We strongly recommend checking the measurements of your bedframe before ordering.

Sometimes, standard mattress dimensions just won’t do. If you have an odd-sized mattress, island bed, round bed, or even a caravan or motorhome bed, you may need to consider a made to measure mattress that’s perfectly made to fit your space. At Custom Size Beds, we provide a wide range of bespoke bed and mattress options to suit a variety of spaces and awkward-sized rooms. Get a quote for your made to measure mattress here.

How to measure a mattress

To ensure you get the best-fitting mattress for your space, it is important to take accurate measurements of your current mattress and the space you have around it. Without accurate measurements, you may end up with a mattress fits awkwardly and compromises your enjoyment.

  • Remove sheets and pillows

    To get the most accurate measurements of your mattress, remove all bedsheets, pillows, and blankets. Leaving bedding on your mattress while measuring can result in inaccurate measurements.

  • Consider measuring the bed frame

    Sometime it can be tricky to measure an old mattress, so you may wish to consider taking measurements of the bed frame directly. If your mattress sits inside walls or a frame, be sure to reduce your overall width/length by 2cm to allow room for tucking in sheets.

  • Measure the length

    Carefully measure the length of your mattress from the head end, down to the foot end. Use a tape measure for the most accurate results. If your mattress is shaped, ensure you measure from the longest point. Remember to write down the measurements so you don’t forget!

  • Measure the width

    Use a tape measure to measure from left to right across the width of your mattress. If your mattress is shaped, ensure to measure the widest point.

  • Measure the thickness

    Once again, take your tape measure to measure from the top to bottom the thickness of your mattress.

Knowing the size of your mattress allows you to correctly order a new mattress which fits. Mattress sizes differ depending on the width and length.

If you have an odd-sized mattress

If you have an odd-sized space for your mattress that has irregular dimensions, diagonal corners, or obstructions, such as pillars and posts, our odd size mattresses ensure a perfect fit.

Our website allows you to design your mattress to your space perfectly by selecting the shape and size of your mattress. Measure your space with a tape measure and submit your dimensions to generate a quote for your odd-size mattress cut to any size.

Custom Size Beds, your best choice

Don’t compromise on the quality of your sleep, instead make the most of your awkward spaces with a bespoke mattress from Custom Size Beds.

No matter the shape or size of your current mattress our website allows you to either order or request a quote for a perfectly fitting mattress. Mattresses can be cut to any size and shape to fit corners, posts, and irregular bed frames.

Odd-size mattresses can also be made for campervans, motorhomes, caravans, boats, and even trucks, so you can enjoy a comfy, well-fitted mattress at home and while on the go. For more information about our custom-size beds and mattresses, get in touch with our expert team today. The team are on hand to help and ready to answer any questions you may have.

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Start by selecting the shape that shows the closest match to your requirements – you’ll be able to customise this later. If you can’t find your shape or need something entirely different, get in touch and we’ll be more than happy to help.

Step 1) Select the shape you wish to customise
Basic shapes
Shaped mattresses
You’ll select which side the shape is cut later
Split mattresses
You’ll select the position of the split later