Key TakeawaysWait Time for Memory Foam Mattresses: When you receive a new memory foam mattress in a box, it’s common for manufacturers to recommend waiting 24-48 hours before using it. This waiting period allows the mattress to fully expand and take on its intended shape. Waiting ensures that any defects or issues become visible, and it gives time for off-gassing, which typically occurs in the initial hours.Sleeping Before 24 Hours: While it’s recommended to wait, sleeping on the mattress before 24 hours won’t ruin it. Manufacturers provide a buffer in their instructions, and in some cases, sleeping on the mattress can even expedite the expansion process. Body heat can make the memory foam more pliable, aiding in quicker expansion.Determining the Right Side and Additional Tips: To determine which side of the expanded mattress faces up, check for a tag or label. The side with the tag should face up when placing the mattress on the bed frame. Memory foam is temperature-sensitive, and warming it can make it more flexible, expediting the expansion process. Raising the room temperature or using body heat can contribute to quicker expansion.You arrive home to find your new memory foam mattress at your doorstep. Your excitement is high as you begin to unbox the newest addition to your home. As you read the directions, your excitement hits rock bottom when you realize you are not supposed to sleep on it for 24 hours.Everything is ready for this mattress to takes its place in your sleep sanctuary. Slats are placed perfectly for a firm foundation. The old mattress and box spring have been removed and discarded. Mattress topper and protector are ready. You just can not wait to crawl into this great mattress and enjoy a restful night’s sleep.You’re thinking, it’s only a couple of hours before bedtime.So, is it true that you should wait 24 hours? What would happen if you did sleep on it before 24 hours has elapsed? Will it be ruined after the first night? This is exactly what we will be discussing. Keep reading to learn why 24 hours is the target number and what happens when you sleep on your new memory foam mattress before 24 hours have elapsed.What is Mattress in a Box?Memory foam mattress manufacturers found success in the online market. The internet allows consumers to research, shop, and buy almost anything. Your purchases are paid for and then shipped, in a box, right to your door. Some companies are so large and efficient they can do all this in 24-48 hours.You may wonder how a mattress is going to fit in a box. Well, the box is now the primary mode of shipping for memory foam mattresses. This means manufacturers can compress, deflate, fold, and stuff a mattress in a box. Unlike traditional innerspring mattresses, memory foam is known for easy shipping and added comfort.Getting a mattress in a box has changed the way we shop and sleep. Memory foam’s ability to be compressed, rolled, and folded is remarkable. All this action and the memory foam does not lose any of its quality. Once your mattress in a box has reached your doorstep, all you need to do is pop the airtight seal, unroll the mattress and watch the expansion process begin. A good night of sound sleep is in your future.Why is it Recommended to Wait 24 Hours Before Use?Waiting 24-48 hours is standard for a memory foam mattress to completely take on its full shape. The reason for this instruction is to cover the manufacturer’s responsibility.They prefer customers to wait 24 hours to allow for the expansion process to be completed. Only after the mattress has reached its full shape can a customer ensure they received the product they paid for. If there is cracking or splitting in the memory foam layer, it will not be visible until the expansion process is complete.This 24-hour recommendation is to ensure customer satisfaction and manufacturer guarantees. It also gives any off-gassing time to dissipate. Usually, off-gassing happens in the first couple of hours.Get resources for better sleepSign up for sleep health education, expert tips, and the latest and greatest mattress sales. Email See Privacy PolicyWhat Will Happen if you Don’t Wait 24 Hours?If you decide that waiting 24 hours is out of the question, have no fear. While the instructions say wait, it is generally okay if you don’t. The manufacturer always errs on the side of caution. Consumers need to follow instructions while understanding that some instructions are recommendations. If you only have a couple of hours, it is okay.In fact, sleeping on your new memory foam bed before 24 hours can speed up the process. Body heat can make the memory foam more pliable, making it expand faster.Only regular wear and tear from sleep can cause deficiencies in your mattress. This is not going to happen in one night. Remember that if you do choose to sleep on your mattress before it is fully expanded, you may not get the full set of benefits that particular night. A memory foam mattress can only provide a plush supportive feel at its full shape. This is why so many online companies offer lengthy sleep trials. A customer-friendly sleep trial allows you to give your new mattress an honest try before deciding if it’s for you or not.To sum it all up, you can expect a rolled up, folded memory foam mattress upon unboxing. If your new bed beckons you before 24 hours, it’s perfectly safe to drift off upon it.If after 24 hours your new mattress has not expanded or you notice defects in the foam, call the manufacturer.Which Side of an Expanded Mattress Faces Up?When your mattress expands into its full shape, you might find yourself in a little pickle, unsure about which side should be facing up. Not all mattresses are two-sided, especially memory foam ones that are designed for sleeping on only one side. But worry not! There are some nifty tricks that can quickly help you solve this riddle.First off, take a peek at the mattress tag or label that’s attached to it. You’ll usually find this tag sewn onto one side of the mattress. Now, here’s the key: if the tag is there, it means the opposite side, without the tag, should be facing up when you place the mattress on your bed frame.Remember, keep the tag side away from the bed frame or the floor. By paying attention to the tag, you can easily figure out how to orient your memory foam mattress correctly and create a cozy sleeping surface. Simply put, when the tag side faces up, you should be able to read the brand and other information on it.Some mattresses also have a clear design that shows which side is up. For example, a mattress may have a sleek quilted top with tufts and a flat bottom of rough, non-skid fabric. The color scheme may also make it clear which way faces up.But if the tag and mattress design don’t give you a clear answer, try feeling the surface on each side. Even if the mattress looks the same on top and bottom, you can still feel a difference. One side should yield more quickly to your touch—it’s the side with the comfy padding where you’re meant to sleep. The firmer side faces down.If all these methods leave you scratching your head, don’t fret! Reach out to the customer service team of your mattress brand. They’ll be happy to assist you in solving the great mattress mystery.Buying a New Mattress Without OverspendingYou don’t need to break the bank to invest in a new memory foam mattress. We suggest one of these top sales that pop up throughout the year:Presidents Day Mattress SalesMemorial Day Mattress Sales4th of July Mattress SalesLabor Day Mattress SalesColumbus Day Mattress SalesBlack Friday Mattress SalesCyber Monday Mattress SalesSEE ALSO: Best Time to Buy a MattressFrequently Asked QuestionsHow long does a memory foam mattress take to inflate?Generally, manufacturers say it takes 24-48 hours for a memory foam mattress to fully inflate. This time frame is not set in stone as each memory foam mattress is unique. Some new mattresses will take longer or even less time. You also do not have to wait a full 24 hours to put on your mattress protector or topper. Also, you can sleep on a mattress on the first night, just know the bed may feel different on night two or three.Does heat help memory foam expand?Memory foam is sensitive to varying temperatures. In cooler rooms, memory foam can seem more firm. If this is the case, you may want to raise the room temperature a few notches. Once memory foam becomes warmer, it tends to be more flexible and thus expand faster. Body heat can also aid in the expansion process.How long should you leave a memory foam mattress before sleeping on it?Once you have received your new memory foam mattress, it is best to open immediately. It takes 4-6 hours for the memory foam to expand 90% and could take another 4-6 hours to get close to full expansion. It is recommended to wait 24 hours before sleeping on it, but don’t worry if you can’t.So, What Happens if You Sleep on a Memory Foam Mattress Before 24 Hours?Memory foam is a product that has given rise to the mattress in a box phenomenon. Most manufacturers boast about their mattress in a box offers. It is completely possible to compress, roll, and even fold a memory foam mattress and place it in a box. No matter what size your mattress is, full size, twin XL, or king, it will fit in a box.It is recommended to wait 24-48 hours before sleeping on a new, memory foam mattress. It is up to the consumer whether to wait or not. Defects will not be as obvious before the expansion process has been completed, but expansion should not slow down because you slept on your new memory foam mattress.The short and simple answer is nothing. Your new mattress may not feel exceptional the first night. As the expansion process continues, it will only get better. Once 24 hours have passed, you should have a new bed with what you will call the best mattress you’ve ever owned.About the author Amy MurphyAmy Murphy has spent the last 7 years experimenting with different apps, exercises, products, and routines to optimize her sleep. From sleep tracking gadgets to polyphasic sleep schedules, she’s tried some of the most unusual recommendations for better shut-eye. As Best Mattress Brand’s lead tester, she’s reviewed dozens of different mattresses and bedding accessories to find her top recommendations. Through her articles, Amy shares the wealth of knowledge she has gained during these experiences so readers can find the best sleep possible. Find more articles by Amy CommentsLeave a comment Carleene January 12, 2020 at 8:46 pm ReplyI just purchased my new 4″ memory foam topper with a copper infusion from Walmart. When we opened it, there were no instructions inside. Just wondering if this is normal with the Alllswell king size topper. I can’t wait to try it out, but I wish it had come with a cover. Maybe there is a reason for this. I will leave a review after we have slept on it. Jim January 30, 2020 at 8:48 am Reply4″ mattress? Sounds like you’re going to be sorely disappointed. Branden February 15, 2020 at 2:25 am ReplyThe Allswell is a 12-inch mattress, the first 4 inches are memory foam and the bottom is made of springs. Sara May 10, 2020 at 2:59 pm ReplyIt’s a mattress TOPPER. Jen May 18, 2020 at 12:57 pm ReplyShe said topper, not mattress Jesse February 16, 2020 at 10:46 am ReplyI just brought mine home from Walmart, my king size 4-inch copper gel didn’t come with a cover, total cost 169.34. I don’t know if I got a deal or not? But I’m satisfied Wendy Hankins November 16, 2020 at 8:20 pm ReplyI bought a 12 inch memory foam mattress from Amazon for $220. I’ll be sleeping on it for the first time tonight Eve July 15, 2020 at 7:23 pm ReplyAt Walmart? ? Lisa February 25, 2021 at 12:36 pm ReplyCarleen, How has this topper worked out? I’m in the process of trying to find the right mattress topper and it’s daunting to say the least, such varying reviews on every single topper. 🤦 Mark May 1, 2020 at 6:14 am ReplyWe have purchased a hybrid mattress and it has not expanded to its advertised size, we have contacted the manufacturer and not really get the resolution that helps, what are the reasons? why it has not expanded correctly and how will to affect its performance? Thanks M Tonie January 11, 2021 at 1:06 am ReplyOur mattress never fully inflated. What a disappointment. Pat Walker March 15, 2021 at 3:38 pm ReplyI have an AC Pacific memory foam 6in mattress with a blue topping it will not inflate why is this I got it as a Christmas gift and no instructions came with it I just opened it 2 days ago Terry Eisenhauer May 2, 2020 at 8:59 am ReplyIm looking for a bed in a box that is SOFT. WHAT DO U SUGGEST AND REASONABLE Roman July 25, 2020 at 1:21 pm Replylayla ! i just bought one and its is most definitely soft as heck Kelley September 24, 2020 at 1:46 pm ReplyZinus brand. We just got it. 12 inch memory foam for only $369. And it’s awesome!!! Best bed I’ve ever had!!! Katherine April 8, 2021 at 12:36 pm ReplyI just got the zinus 12” green tea memory foam mattress and it is hands down the most amazing mattress ever. I laid down for a nap before work and fell asleep in record time. I woke up feeling like i had gotten better rest in 1hr than i ever have in a full nights sleep. I cannot wait to get home from work and sleep an entire 8+ hours on this bad boy. Jeff Cook September 27, 2020 at 12:35 pm ReplyThe Brooklyn Bedding Signature in soft = amazing! I also have their Propel Sleep mattress and it’s amazing as well! Terry Evans December 3, 2020 at 8:51 am ReplyI recommend the the Sleep Cool Plush 13 inch mattress or higher. Maggie May 3, 2020 at 4:35 pm ReplyWhy do they smell Julia November 21, 2020 at 3:54 pm Replymemory foam naturally has a smell and whenever it’s put in a bag and a box the smell will be isolated I guess you could say, so it just needs time to air out ( I recommend opening a window too to air the smell out of your room). I’m fourteen but have joint issues in my back, and I got a memory foam mattress and topper a while ago, and it’s heaven! Bill Ireland May 11, 2020 at 5:08 pm ReplyWe just got a king Puffy Lux 12″ and after unfolding and initial expansion (20 min!) we couldn’t resist the temptation. If it gets any better than this (24 hrs!?) I may never leave the house again! My wife and I are meeting with an arbitrator next week to determine which of us gets buried with it! Annie H December 6, 2020 at 6:42 pm ReplyLol! Rita Harris May 11, 2020 at 8:15 pm ReplyI had to check online to see how long to wait for the mattress to expand. There were no instructions. Jill May 20, 2020 at 12:29 pm ReplyWill A Mel foam mattress expand if I put it in a protector? Judi May 27, 2020 at 7:54 pm ReplyI’m going to have to pick this bed up and take it home. Will it fit in a regular sedan? Debra Palmer June 11, 2020 at 9:41 pm ReplyI was gifted with a Novaform Plush memory foam mattress. It is 14″ thick. I had a memory foam mattress prior to this one, but there is no comparison. I researched the “Bed in a Box” mattresses, and for my money, went with this one. Sleep is very hard for me. I am a 20 plus yr. Chronic Patient who has Fibromyalgia, severe osteo and rheumatoid Arthritis, have had over 110 broken bones, and Multiple Sclerosis. These ruin a good nights’ sleep. This mattress has given it back. My horrible pressure points are unfelt. Moving while sleeping doesn’t awaken me, screaming in pain. I cannot believe the blissful sleep that comes with true comfort. Thank you, Rebecca & David, and thank you, Costco. Radames M. Sosa September 11, 2020 at 1:59 am ReplyMartha, What????? Morticia September 13, 2020 at 3:13 pm ReplyLOL Karenteed September 18, 2020 at 12:35 pm ReplyMe too! Lol Patricia lee December 5, 2020 at 8:28 am ReplyMy mattress sages in the middle? Its been 24 hours . We bought two however the other one is fine. Please help!! NiColla C. September 15, 2020 at 6:13 pm ReplyHuh? John Evans September 18, 2020 at 6:25 pm ReplyIs it bad if you leave it in the plastic during the 24 hour wait period Yvonne Washington September 25, 2020 at 3:09 pm ReplyI don’t have a vacuum cleaner now can I return this mattress ,I almost fell on the floor. Too soft I can’t hardly move like I want to. Kal November 9, 2020 at 1:49 am ReplyIt’s important to take into account your body weight and sleeping posture if you sleep on your back a minimum 10 inch memory foam may be ok but if you are big and you sleep on your side then a minimum of 12 inch upwards is recommended Matt November 25, 2020 at 7:38 pm ReplyThe 14” Lucid gel and memory foam mattress (in a box) is the best mattress my wife and I have ever owned. We went with medium vs plush because we like sleeping on our back and sides, not just sides. Spent just over $500 for the King size mattress and absolutely LOVE it. I have severe back pain and severe arthritis as does my wife. This new mattress is incredible! Also recommended to wait 24 hrs before sleeping on but we slept in after 16 hrs. Opened up. Mattress at least 90% open to full capacity and research shows body heat from 1st night will get full optimum expansion by nt 2. Bought on Amazon. C cameron January 14, 2021 at 7:57 pm ReplyJust got my mattress from wayfair havent slept on it yet its been opened for 8 hours feels fantastic Meganolia February 1, 2021 at 11:14 pm ReplyIm a widow and decided on a twin bed. I paid $500+ for a wonderful mattress. Laid on it in show room floor. Bought it and agreed on delivery. I got it and within minutes I laid on it. It was like a brick. So I called the company and they said $199 restocking fee. I went to wayfair and got a gorgeous lavender twin size memory foam topper. I saved $150 but doing the topper without paying to return it and pay $199. Tin March 3, 2021 at 7:28 am ReplyWhat happens if you don’t open the bed in box immediately (3-4 days after delivery)? Will it ruin the mattress? Shirley S Swaim March 9, 2021 at 4:37 am ReplyTin I received my bed in the box on Wednesday last week but I cannot take it apart and open it up and put it into my bedroom by myself and I don’t have help till next week and I’m wondering is it going to hurt it to stay in it a week or two before I get it open imagine it’s probably been sitting in the warehouse for months but I’m just curious about the same thing let me know if you get an answer Cassie March 14, 2021 at 11:06 am ReplyWe have had our memory foam mattress for 48 hours. Only one half had begun to expand but not nearly close to the 12 inches. This is a Zinus mattress. Has anyone else had a problem like this? The company’s advice is to be patient but we are running out of that because we see no improvement. Ken April 12, 2021 at 1:53 pm ReplyBought the Ashley Chime 12” memory foam mattress in medium firmness do to chronic lower back pain do to disc pinching nerves and all I can say is wow and reached 90% shape in an hour. Came from Amazon for $260 best bed purchase I’ve made!!! Cindy April 12, 2021 at 3:44 pm ReplyWe bought an AWESOME 14′ Classic Brand Mattress on Amazonfor $461.00 and it came with 2 AWESOME PILLOWS. IT’S LIVING UP TO EVERYTHING WE EXPECTED!!! Leave a comment Cancel replyLeave a CommentYour email address will not be published. Required fields are marked * Comment Name Email I agree to the Privacy Policy of this website. Δ
Carleene January 12, 2020 at 8:46 pm ReplyI just purchased my new 4″ memory foam topper with a copper infusion from Walmart. When we opened it, there were no instructions inside. Just wondering if this is normal with the Alllswell king size topper. I can’t wait to try it out, but I wish it had come with a cover. Maybe there is a reason for this. I will leave a review after we have slept on it.
Jim January 30, 2020 at 8:48 am Reply4″ mattress? Sounds like you’re going to be sorely disappointed.
Branden February 15, 2020 at 2:25 am ReplyThe Allswell is a 12-inch mattress, the first 4 inches are memory foam and the bottom is made of springs.
Jesse February 16, 2020 at 10:46 am ReplyI just brought mine home from Walmart, my king size 4-inch copper gel didn’t come with a cover, total cost 169.34. I don’t know if I got a deal or not? But I’m satisfied
Wendy Hankins November 16, 2020 at 8:20 pm ReplyI bought a 12 inch memory foam mattress from Amazon for $220. I’ll be sleeping on it for the first time tonight
Lisa February 25, 2021 at 12:36 pm ReplyCarleen, How has this topper worked out? I’m in the process of trying to find the right mattress topper and it’s daunting to say the least, such varying reviews on every single topper. 🤦
Mark May 1, 2020 at 6:14 am ReplyWe have purchased a hybrid mattress and it has not expanded to its advertised size, we have contacted the manufacturer and not really get the resolution that helps, what are the reasons? why it has not expanded correctly and how will to affect its performance? Thanks M
Pat Walker March 15, 2021 at 3:38 pm ReplyI have an AC Pacific memory foam 6in mattress with a blue topping it will not inflate why is this I got it as a Christmas gift and no instructions came with it I just opened it 2 days ago
Terry Eisenhauer May 2, 2020 at 8:59 am ReplyIm looking for a bed in a box that is SOFT. WHAT DO U SUGGEST AND REASONABLE
Roman July 25, 2020 at 1:21 pm Replylayla ! i just bought one and its is most definitely soft as heck
Kelley September 24, 2020 at 1:46 pm ReplyZinus brand. We just got it. 12 inch memory foam for only $369. And it’s awesome!!! Best bed I’ve ever had!!!
Katherine April 8, 2021 at 12:36 pm ReplyI just got the zinus 12” green tea memory foam mattress and it is hands down the most amazing mattress ever. I laid down for a nap before work and fell asleep in record time. I woke up feeling like i had gotten better rest in 1hr than i ever have in a full nights sleep. I cannot wait to get home from work and sleep an entire 8+ hours on this bad boy.
Jeff Cook September 27, 2020 at 12:35 pm ReplyThe Brooklyn Bedding Signature in soft = amazing! I also have their Propel Sleep mattress and it’s amazing as well!
Terry Evans December 3, 2020 at 8:51 am ReplyI recommend the the Sleep Cool Plush 13 inch mattress or higher.
Julia November 21, 2020 at 3:54 pm Replymemory foam naturally has a smell and whenever it’s put in a bag and a box the smell will be isolated I guess you could say, so it just needs time to air out ( I recommend opening a window too to air the smell out of your room). I’m fourteen but have joint issues in my back, and I got a memory foam mattress and topper a while ago, and it’s heaven!
Bill Ireland May 11, 2020 at 5:08 pm ReplyWe just got a king Puffy Lux 12″ and after unfolding and initial expansion (20 min!) we couldn’t resist the temptation. If it gets any better than this (24 hrs!?) I may never leave the house again! My wife and I are meeting with an arbitrator next week to determine which of us gets buried with it!
Rita Harris May 11, 2020 at 8:15 pm ReplyI had to check online to see how long to wait for the mattress to expand. There were no instructions.
Judi May 27, 2020 at 7:54 pm ReplyI’m going to have to pick this bed up and take it home. Will it fit in a regular sedan?
Debra Palmer June 11, 2020 at 9:41 pm ReplyI was gifted with a Novaform Plush memory foam mattress. It is 14″ thick. I had a memory foam mattress prior to this one, but there is no comparison. I researched the “Bed in a Box” mattresses, and for my money, went with this one. Sleep is very hard for me. I am a 20 plus yr. Chronic Patient who has Fibromyalgia, severe osteo and rheumatoid Arthritis, have had over 110 broken bones, and Multiple Sclerosis. These ruin a good nights’ sleep. This mattress has given it back. My horrible pressure points are unfelt. Moving while sleeping doesn’t awaken me, screaming in pain. I cannot believe the blissful sleep that comes with true comfort. Thank you, Rebecca & David, and thank you, Costco.
Patricia lee December 5, 2020 at 8:28 am ReplyMy mattress sages in the middle? Its been 24 hours . We bought two however the other one is fine. Please help!!
John Evans September 18, 2020 at 6:25 pm ReplyIs it bad if you leave it in the plastic during the 24 hour wait period
Yvonne Washington September 25, 2020 at 3:09 pm ReplyI don’t have a vacuum cleaner now can I return this mattress ,I almost fell on the floor. Too soft I can’t hardly move like I want to.
Kal November 9, 2020 at 1:49 am ReplyIt’s important to take into account your body weight and sleeping posture if you sleep on your back a minimum 10 inch memory foam may be ok but if you are big and you sleep on your side then a minimum of 12 inch upwards is recommended
Matt November 25, 2020 at 7:38 pm ReplyThe 14” Lucid gel and memory foam mattress (in a box) is the best mattress my wife and I have ever owned. We went with medium vs plush because we like sleeping on our back and sides, not just sides. Spent just over $500 for the King size mattress and absolutely LOVE it. I have severe back pain and severe arthritis as does my wife. This new mattress is incredible! Also recommended to wait 24 hrs before sleeping on but we slept in after 16 hrs. Opened up. Mattress at least 90% open to full capacity and research shows body heat from 1st night will get full optimum expansion by nt 2. Bought on Amazon.
C cameron January 14, 2021 at 7:57 pm ReplyJust got my mattress from wayfair havent slept on it yet its been opened for 8 hours feels fantastic
Meganolia February 1, 2021 at 11:14 pm ReplyIm a widow and decided on a twin bed. I paid $500+ for a wonderful mattress. Laid on it in show room floor. Bought it and agreed on delivery. I got it and within minutes I laid on it. It was like a brick. So I called the company and they said $199 restocking fee. I went to wayfair and got a gorgeous lavender twin size memory foam topper. I saved $150 but doing the topper without paying to return it and pay $199.
Tin March 3, 2021 at 7:28 am ReplyWhat happens if you don’t open the bed in box immediately (3-4 days after delivery)? Will it ruin the mattress?
Shirley S Swaim March 9, 2021 at 4:37 am ReplyTin I received my bed in the box on Wednesday last week but I cannot take it apart and open it up and put it into my bedroom by myself and I don’t have help till next week and I’m wondering is it going to hurt it to stay in it a week or two before I get it open imagine it’s probably been sitting in the warehouse for months but I’m just curious about the same thing let me know if you get an answer
Cassie March 14, 2021 at 11:06 am ReplyWe have had our memory foam mattress for 48 hours. Only one half had begun to expand but not nearly close to the 12 inches. This is a Zinus mattress. Has anyone else had a problem like this? The company’s advice is to be patient but we are running out of that because we see no improvement.
Ken April 12, 2021 at 1:53 pm ReplyBought the Ashley Chime 12” memory foam mattress in medium firmness do to chronic lower back pain do to disc pinching nerves and all I can say is wow and reached 90% shape in an hour. Came from Amazon for $260 best bed purchase I’ve made!!!
Cindy April 12, 2021 at 3:44 pm ReplyWe bought an AWESOME 14′ Classic Brand Mattress on Amazonfor $461.00 and it came with 2 AWESOME PILLOWS. IT’S LIVING UP TO EVERYTHING WE EXPECTED!!!