Cot and Cot Bed Size Guide

3 Boori cots and cot beds with dimensions

As parents, nursery furniture - and the pièce de résistance that is your cot or cot bed – is the most important purchase you’ll make when preparing for your new baby, so it’s important to have the 4-1-1 before you splurge.

When it comes to specific cot and cot bed sizes, here’s everything we think you need to know ahead of your baby arriving…

What size cot should I buy?

There isn’t a one-size-fits-all answer, as it depends on several factors which will be unique to you, but you need to consider the below for your baby bed:

  • Your nursery size
  • How much space is available to fit furniture
  • The furniture already in the room that cannot be removed
  • The additional furniture you have purchased, or plan to purchase, for your baby nursery (and how much space it takes)
  • How long you’d like your child to use it
  • If you'd like your child to use the cot longer-term, consider if they'll have the same bedroom as they grow. If it's likely they won't have the same bedroom, consider whether the style and colour is likely to fit your interior style later.

When you’re looking at what size cot you should buy, remember cot and cot bed sizes vary from brand to brand, and within that, from model to model. This applies to both the assembled size of a cot or or cot bed, plus the mattress, bedding and mattress protector size that fits them.

Cot vs. Cot Bed

A cot is much smaller in size and traditionally comes with a petite frame, which is great for parents working with a small baby nursery layout. Cot beds are more experimental in design and bring longevity, lasting a child up to approximately 5 years old.


Unless your baby nursery is in a loft conversion or quaint low ceiling property, don't worry about the height of the frame. However, if you’re looking to decorate your nursery around the height, then this measurement will be important.

Instead, the main areas of difference you’ll want to be clued up on are the width and length of the assembled cot or cot bed, as these are what will take up most floor space.

The smallest width within our range is 70cm (like our Oasis Oval Cot), with the largest being 84cm (like some of our cot beds). There’s only a 14cm difference, which doesn’t sound like much, but might be the difference between storage space for those baby essentials or not.

The length is also an important dimension, as the length difference between our models is much more noticeable than the 14cm we just mentioned. The smallest lengths are within our compact cot range, with the largest length (157cm) being on our Sleigh Royale Cot Bed.

Whilst the assembled sizes of our cots and cot beds vary, the mattress sizes remain consistent:

  • A Boori compact cot requires a 119cm x 65cm mattress size
  • A Boori cot bed requires a 132cm x 70cm mattress size
  • The Boori Oasis Oval Cot requires a 119cm x 64cm oval mattress size
  • The Boori Nova Cot Bed requires the Nova Purotex Cot Bed Mattress with a size of 132cm x 70cm

diagram of cot base sizes


Whilst our range of compact cots and cot beds can be easier on the purse strings in the short-term, our Eton Convertible Plus Cot Bed will provide added value to you in the long term, as it will take your incoming arrival or newborn baby way into their teenage years as it can convert into a full-sized double bed and cosy sofa (Conversion kit required).

eton cot bed converting into a double bed

If you want your baby's cot to fit ‘the now’, the Eton might not be for you. Instead, we recommend a cot bed if you have the space, as it will provide more longevity than a cot and will make the transition out of the cot to a toddler bed easier for your baby and you as parents.

Cot Sizes and Cot Bed Sizes

With so many cot and cot bed sizes out there, it’s important to have the correct information when it comes to decision making.

In this section we dive deeper into the assembled dimensions of our cots and cot beds so you can plan your baby nursery layout and purchase the correct mattress, mattress protector and bedding.

FYI: the assembled dimensions of the cots and cot beds will vary (and will appear larger than the required mattress size), as this takes into consideration things like the overall thickness of the frame for example, so don’t be alarmed if the numbers aren’t adding up for you.

Unique cots 

3 uniquely designed cots

Product details

Assembled Dimensions

Mattress size required






Oval Cots

Oasis Oval Cot





Requires an Oval Cot Mattress size of 119cm x 64cm.

Other Unique Cots

Nova Cot Bed





Requires the Nova Purotex Cot Bed Mattress (132cm x 70cm).

The Oasis Oval Cot is unique due to its circular shape, so we have designed an equally unique Oval Cot Mattress and Oval Cot Bedding to match.

Similarly, our Nova Cot Bed also has its own unique mattress, which is sold with the cot bed as a bundle. Our cot bed bedding will fit this mattress.

Our Cot Beds

3 cot beds

Our range of Cot Beds measure in as the largest on average, both in terms of assembled frame dimensions and mattress size, but the assembled dimensions of some of our cot beds are more compact than other brands. 

Product details

Assembled Dimensions

Mattress size required






Cot Beds

Turin Cot Bed





132cm x 70cm.

Sleigh Royale Cot Bed





Neat Cot Bed





Natty Cot Bed





Sleigh Urbane Cot Bed





Alice Cot Bed





All of our Cot Beds require our 132cm x 70cm cot bed mattresses, which fits our cot bed bedding of the same size.

Expandable Cot Beds

3 cots that can be expanded into beds

When it comes to the mattress and bedding required for our Expandable Cot Beds, they require our 132cm x 70cm cot bed mattresses and cot bed bedding. The standard size for all Boori cot beds but unique to us.

These Cot Beds feature our unique conversion technology, meaning these beds transform into a toddler sized bed and single bed when you’re ready (and with the correct conversion kit).

Product details

Assembled Dimensions

Mattress size required







Eton Expandable Cot Bed





132cm x 70cm.

Convertible Plus Cot Beds

3 cots that can be converted into beds

Product details

Assembled Dimensions

Mattress size required







Eton Convertible Plus Cot Bed





132cm x 70cm.

Determining the correct size of a cot mattress

When it comes to the size of a cot mattress, our range of Space Saving Compact Cots are smaller than the standard cot size in the UK. The standard measurement of a cot mattress is approximately 124cm x 64cm, with ours measuring at 119cm x 65cm.  

The standard size of a cot bed mattresses is also larger than a Boori cot bed. The standard size of a cot bed mattress is 140cm x 70cm, with our cot bed mattresses coming in slightly smaller at 132cm x 70cm.

For our unique cots and cot beds (Oasis Oval Cot and Nova Cot Bed), these will require an equally unique mattress, which have both been designed specifically to fit them.

If you're currently looking for nursery furniture, we think you'll be interested in this blog post on setting a baby sleep routine and this one on whether cot bumpers are safe.

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