How Do I Choose the Best Mattress for My Bed?

You can choose the best mattress for your bed by evaluating your existing mattress and bed frame.

Not only is it important to find the perfect mattress for you, but it's also just as essential that the mattress is a good match for your bed.

In this guide, we will take a look at how to choose a mattress for an existing bed. We will detail exactly how to measure your bed frame accurately and why, in some cases, it may be better to purchase a new bed frame for your mattress.

Silentnight Bloomsbury Silver Velvet Bed Frame
Choose from a wide variety of mattresses and beds!

How to choose a new mattress for your current bed

When you're choosing a new mattress for your current bed, you'll need to make sure that:

1. Your bed is a good match

Not every mattress will be compatible with every bed. If you have a bed frame with slats, check that the gaps between them are no greater than 7cm (approximately 2.8 inches). A gap wider than this may cause damage to your new mattress.

2. Your new mattress will fit your bed

You should ensure that your new mattress will fit your bed by measuring your bed. We recommend allowing a +/- 1 inch (2.54cm) tolerance in the stated width and length of your new mattress. This is because it's not always possible for a manufacturer to make a precise size, particularly for pocket sprung mattresses.

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Consider whether you also need a new bed

When pairing a new mattress with an old bed frame it is important to take care. If your bed frame shows any signs of damage such as broken slats or loose screws, this can damage your new mattress.

However, if your bed is relatively new or still in good condition, you should have no issues upgrading your mattress.

If you're buying a new mattress for an existing bed, consider the bed's age and condition. Ask yourself:

  • Has it seen better days?
  • Does it have slats and if so, are they sagging, bent or broken?
  • If your bed is a divan, is the base still in good condition?

If you're unsure about any of the above, it may be a better investment to purchase a new bed frame or divan base.

You can find more advice on choosing the right bed frame in our bed buying guide.

Silentnight Rio Miracoil Cushion Top Divan
Why not check out our collection of divan beds and find the perfect one for you, like the Silentnight Rio?

Browse our full beds range

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How to measure your bed for a new mattress

Before shopping for a new mattress, you should take the inside measurements of your bed.

  1. Using a tape measure, measure the inside length of the bed frame (where the mattress sits) from top-to-bottom. Then, measure the inside width of the bed frame, from side to side.
  2. If you have a divan, take the measurements from the top where the mattress would sit flush with each of the divan sides.
  3. Jot down these dimensions and use them for reference as you're shopping for a new mattress.
  4. Make sure that your new mattress isn't any larger than the measurements you have, though you can choose one which is around 1 inch (2.54cm) smaller.
A close shot of several measuring tapes laid down together.
It's essential to measure your bed before shopping for a new mattress

Here at Mattress Online, we offer a wide range of mattresses in a huge variety of sizes. Below is an overview of our most popular mattress sizes. For more size options, please visit our bed and mattress size guide.

Single mattress3' x 6'3"90cm x 190cm
Small Double mattress4' x 6'3"120cm x 190cm
Double mattress4'6" x 6'3"135cm x 190cm
King Size mattress5' x 6'6"150cm x 200cm
Superking mattress6' x 6'6"180cm x 200cm

These measurements are based on the industry standard, but there are sometimes small differences between certain mattresses and manufacturers. When shopping for an existing bed, it's always best to measure your bed to ensure a good fit.

For a more in-depth explanation of the different bed and mattress sizes, our 'Bed and Mattress Size Guide' has everything you need to know.

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Shopping for your new mattress

When shopping for your new mattress, keep the measurements you have taken close to hand and compare them with the measurements found on all our mattresses. You can choose a mattress that's approximately 1 inch (2.54cm) smaller than you need but certainly no larger.

Which type of mattress should I choose for my bed frame?

The type of mattress you choose will depend entirely on your personal preference and what’s most comfortable for you. However, some bed frames can make your mattress feel a little firmer or softer, depending on the one you choose.

For example, a bed frame with solid slats offers very little give, so it can make your mattress feel firmer. In contrast, sprung slats are curved, so they offer more gentle support, which could make your mattress feel slightly softer and bouncier.

We always recommend choosing a mattress based on the support you require, rather than the bed frame you have.

Buying your mattress

Once you find a mattress that seems like a good fit you can simply order, sit back and enjoy fast, Free Next-Day Delivery!

When your mattress arrives, we do recommend testing the mattress for size on your bed before unwrapping it.

Ensuring the perfect pairing between your bed and mattress is extremely important. It can provide you with years of good quality, supportive sleep. It really is time well invested!

Shop all mattresses today

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At Mattress Online, it's so easy to compare not only measurements but prices and specifications across all our mattresses

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Need a unique size?

Your bed may be a unique size and need a specific mattress size. If you're struggling to find one on our site, please don't hesitate to get in touch - we'll be very happy to help!

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Best-selling divans

If you're interested in our divans, why not take a look at some of our best-sellers below:

Silentnight Vilana Limited Edition Miracoil Divan

1. Silentnight Vilana Limited Edition Miracoil Divan Bed Set

  • From £361.95
  • Miracoil 3-Spring System
  • Supportive, firm feel
Silentnight Ortho Dream Star Miracoil Divan

2. Silentnight Ortho Dream Star Miracoil Divan Bed Set

  • From £401.95
  • Orthopaedic, extra firm rating - great for your back!
  • Miracoil 3-Spring system
Silentnight Slate Grey Divan Bed

3. Silentnight Slate Grey Divan Bed

  • From £209.95
  • Available with two side drawers
  • Platform top divan base

View our divan collection

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Best-selling bed frames

If you think it’s time to invest in a new bed frame as well as a new mattress, take a look at some of our most popular bed frames below:

The LPD Pierre Velvet Bed Frame in a white bedroom with a wooden side table - one of our Top 5 Recommended Beds 2023
  1. LPD Pierre Aqua Velvet Bed Frame
  • From £359
  • Contemporary velvet bed frame with a pop of colour
  • Chic buttoned headboard
Time Living Tetras Metal Bed Frame

2. Time Living Tetras Metal Bed Frame

  • From £159.95
  • Sprung slats for cushioned support
  • Available with a black or silver metal frame
The Silentnight Bloomsbury Silver Velvet Bed Frame in a large bedroom in front of tall windows - one of our Top 5 Recommended Beds 2023

3. Silentnight Bloomsbury Silver Velvet Bed Frame

  • From £739
  • Choose from 2- or 4-drawer storage options
  • Soft touch velvet with beech-effect legs

View our bed frame collection

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Now you know how to choose the best mattress for your bed! Why not check out our extensive collection of mattresses and find the perfect one for you? If you’re also looking for a matching bed, check out our divans and bed frames, too.