How Long Does A Memory Foam Mattress Take To Expand?

Getting a new memory foam mattress is exciting, but wondering about how long it takes for it to fully expand can be frustrating. To know the right duration, it is first important to have the manufacturer’s guidance. When it comes to their guidance, did you know that most manufacturers recommend waiting at least 24 to 72 hours before sleeping on the mattress?

Therefore, to know the exact timing, we’ll delve into the factors affecting expansion time and share useful tips to expedite the process without compromising the integrity of your new sleep surface.

Ready to get that Z’s sooner? Let’s dive right in!

The Standard Expansion Time for Memory Foam Mattresses

The standard expansion time varies, but it typically takes 24 to 72 hours for them to fully expand.

How long does it take for a memory foam mattress to fully expand?

Memory foam mattresses generally take around 24 to 72 hours to fully expand. The exact time can vary based on factors like temperature and the specific model of the mattress. Despite some expanding as quickly as within a few short hours up until nearly full size, complete expansion often occurs in about one to three days. The reason for this duration is due to how most memory foam mattresses are shipped.

Manufacturers commonly vacuum-seal and roll these mattresses into tight packaging for easier handling and transport. This process compresses the mattress, allowing it to fit inside a manageable-sized box.

Once you unbox your new mattress at home and remove all its packaging materials, oxygen starts entering back into the foam cells.

Initially rising quite fast, it could reach approximately 90% of its full size in just 4-6 hours after unboxing, depending on room conditions such as temperature and humidity, which influence how long it takes for a memory foam mattress to fully expand. Following that initial rapid rise, further expansion slows down significantly, with the remaining percentage occurring over an additional period of anywhere from another day up to three more days typically.

If you’ve been waiting even longer than this extended period—say over seven days—and you’re still not seeing your mattress reaching its intended shape or height, then something might be wrong, potentially with either your specific unit received or perhaps sub-optimal environmental conditions for the necessary optimal expansion.

It’s crucially important not only from the perspective of achieving desired comfort levels but also in terms of maximizing life span usage expectancy out of product bought that consumers allow their newly purchased memory foams enough suitable time frame necessary towards adequately expanding: both before commencing utilization as well as overtly avoiding prematurely sleeping atop any freshly unpacked units regardless temptation simply diving into using right off the bat straight away! Unpacking odors will additionally dissipate following several successive days post-unboxing ordinarily; remember to always follow the manufacturer’s instructions provided in the included package upon receiving the order.

Also Read: When Is The Best Time To Buy A Mattress?

Factors Affecting Memory Foam Mattress Expansion

High-density memory foam mattresses expand faster than their low-density counterparts due to their superior cell structure. The mattress’s expansion can also be impeded by the compression it experiences during packaging.

These density and compression factors, coupled with temperature sensitivity, play crucial roles in determining the duration of a memory foam mattress’s expansion. For instance, cold temperatures cause the foam to stiffen and slow down its expansion rate.

On the other hand, warmer conditions facilitate quicker expansion as they soften up the foams more rapidly. Furthermore, improper air circulation around your new mattress may hinder its ability to fully expand and reach its intended size in time.

Understanding these factors can aid you in creating an optimal environment for your new memory foam mattress to reach full size swiftly and efficiently.

Mattress Compression During Packaging

Manufacturers compress memory foam mattresses into smaller packages to make shipping easier and more efficient. This process involves removing air from the mattress, reducing it drastically in size.

They then seal this compressed form in protective plastic wrap and place it inside a box for transport. The high-density foam can withstand this compression without damage or loss of quality.

Once you remove your new memory foam mattress from its package, it begins expanding back to its original shape immediately but may require up to 72 hours for full expansion. It’s essential to consider this factor when scheduling your mattress delivery and setting up your bedroom arrangement.

Temperature sensitivity

How Long Does A Memory Foam Mattress Take To Expand

Memory foam mattresses are known for their temperature sensitivity. This means that the expansion can be influenced by the room temperature at which the mattress is placed.

When the environment is colder, it may take a longer time for the mattress to fully expand. On the other hand, warmer temperatures can speed up the expansion. It’s important to note that extreme temperatures should be avoided, as they can negatively affect memory foam mattresses.

By ensuring a moderate and comfortable room temperature, you can help facilitate the full expansion of your memory foam mattress within the recommended timeframe of 24 to 72 hours.

Cell structure

cell structure in mattress compression for How Long Does A Memory Foam Mattress Take To Expand

The cell structure of a memory foam mattress plays a crucial role in its expansion process. Memory foam is made up of tiny cells that contain air or gas, which allows the foam to compress and then expand back to its original shape.

When a memory foam mattress is compressed and vacuum-packed for shipping, these cells are compressed as well. Once the mattress is unpacked, it needs time for these cells to regain their original size and shape.

The larger the size of the mattress, the longer it may take for the cells to fully expand. Patience is key when waiting for your memory foam mattress to reach its full expansion potential.

Tips on Expediting Memory Foam Mattress Expansion

To expedite the memory foam mattress expansion, individuals can adjust the room temperature, apply gentle pressure to the mattress, rotate or flip it, massage the foam, and ensure proper air circulation.

Adjusting room temperature

Adjusting the room temperature can help expedite the expansion of a memory foam mattress. Keeping the room warm, between 70-75 degrees Fahrenheit, can encourage the foam to fully expand quicker.

Warmer temperatures soften the foam and make it more pliable, allowing it to regain its original shape faster. On the other hand, colder temperatures can slow down expansion and make the foam feel firmer for longer periods.

Therefore, ensuring a comfortable room temperature is an effective way to speed up the memory foam mattress’s expansion and enjoy a restful night’s sleep sooner.

Applying gentle pressure

Gently applying pressure to a memory foam mattress can help expedite the expansion. This can be done by simply pressing down on different areas of the mattress, focusing on any compressed corners or uneven spots.

By doing so, you are helping to distribute air and encourage the foam cells to expand more quickly. However, it’s important to note that the pressure should be gentle and not excessive, as too much force could potentially damage the mattress.

It’s best to follow the manufacturer’s instructions and allow for enough time for the mattress to fully expand naturally while occasionally applying gentle pressure if desired.

Rotating or flipping the mattress

Rotating or flipping the mattress can help expedite the memory foam mattress expansion. By rotating the mattress from top to bottom or flipping it over, you encourage an even distribution of pressure and airflow throughout the foam cells.

This movement allows for faster and more uniform expansion, ensuring your mattress reaches its full size as quickly as possible. Remember to refer to the manufacturer’s instructions before rotating or flipping your memory foam mattress to ensure proper care and maintenance.

Massaging the foam

Massaging the foam of a memory foam mattress can help expedite the expansion. Gently pressing and kneading the areas that are slow to expand can encourage the trapped air to escape, allowing the foam to reach its full size more quickly.

This can be done by applying gentle pressure with your hands or using circular motions to massage specific areas. However, it’s important not to apply excessive force or use sharp objects, as this could damage the foam.

By massaging the foam, you can help ensure that your memory foam mattress expands evenly and provides optimal comfort and support for a good night’s sleep.

Ensuring proper air circulation

Proper air circulation is essential for the memory foam mattress to expand correctly. It helps distribute the heat evenly throughout the mattress, allowing it to reach its full expansion potential.

Make sure that the room where you place the mattress has good ventilation and is not too humid or damp. Avoid covering the mattress with any heavy blankets or sheets during the expansion, as this can trap heat and hinder proper airflow.

Additionally, ensure that no obstacles are blocking the flow of air around the mattress. By ensuring proper air circulation, you can help facilitate a faster and more effective expansion of your memory foam mattress.

What Happens If You Sleep on a Memory Foam Mattress Before 24 Hours?

Sleeping on a memory foam mattress before 24 hours have passed can affect its ability to fully expand. When you sleep on the mattress too soon, it may not have had enough time to regain its proper shape and size.

This can result in an uneven sleeping surface, which may impact the overall comfort and support provided by the mattress. Additionally, sleeping on a partially expanded memory foam mattress can put extra pressure on certain areas of the foam, causing it to wear out faster over time.

To ensure the best performance and longevity of your memory foam mattress, it’s important to wait until it has fully expanded before using it for sleep.



In conclusion, memory foam mattresses can take anywhere from 24 to 72 hours to fully expand. It’s important to allow the mattress enough time to reach its intended size before using it. Also, it is equally important to follow the guidelines provided by the manufacturer. Thus, following the manufacturer’s instructions and being patient during the expansion will ensure optimal comfort and support for a restful night’s sleep on your memory foam mattress.


How long does it take for a memory foam mattress to expand fully?

A memory foam mattress typically takes about 24-48 hours to fully expand after unpacking.

Can I sleep on a memory foam mattress before fully expanding?

It is recommended to wait until the memory foam mattress has fully expanded before sleeping on it for optimal comfort and support.

What should I do if my memory foam mattress doesn't fully expand?

If your memory foam mattress doesn't fully expand within the expected timeframe, try removing any packaging or coverings that may be restricting its expansion and allowing more time for it to expand naturally.

Is there anything I can do to speed up the expansion process of a memory foam mattress?

To expedite the expansion process of a memory foam mattress, you can gently massage or pat areas that haven't fully expanded and ensure proper ventilation in the room by opening windows or using fans.


Stephani (she/her) serves as the Executive Director of Strategy and Operations at, where she conducts comprehensive research, testing, and analysis of fabric-based products spanning sheets, mattresses, towels, pillows, fitness apparel, and other clothing items..Read more

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