Why do mattress weight limits exist—and do they matter?

Many mattress manufacturers point to a specific amount of weight that shouldn’t be exceeded. Sometimes it’s 500 pounds per person, other times it’s 650 or 700 pounds per mattress. Some companies don’t say anything about maximum weight thresholds. All those numbers got us wondering, just how important are weight limits—and why do they exist in the first place?

What is a mattress weight limit?

Weight limits are exactly what they sound like: suggested caps on the amount of weight, and thereby pressure, customers should put on a mattress. The limits have been around for years, says Byron Golub, the director of product and merchandising at Saatva. Older brands built limits into their warranty policies as a means of protection, he explains. (In this case, it likely strengthened the policies for the company and made things worse for consumers, especially those in higher weight groups.)

Weight limits are sometimes clearly advertised on product pages or in company FAQs. The numbers could also be squeezed into the fine print of a warranty policy, according to Golub.

At Reviewed, we’ve scoured dozens of warranties as part of our comprehensive testing on our quest to find the best mattresses in a box. While shopping, we suggest digging into any brand you’re considering. Pull up a warranty page online, then hit “command + F” on Apple devices or “ctrl + F” on Windows. Try keywords such as “weight,” “pounds,” or “limit” to discover whether the brand addresses the subject. If that’s coming up empty, consider chatting with customer service agents. In general, we find online reps to be helpful with our questions and often answer quickly.

Why do mattresses have weight limits?

Mattress materials are like anything else—they can only withstand so much use before breaking down. (To determine if you need to replace your mattress, look for signs such as sagging or divots in the surface of the bed that could indicate it's not as supportive as it once was.)

Higher weight loads wear out mattresses more quickly, according to Jeff Brown, the president of Big Fig, a company that designs mattresses with higher weight limits. Most mattresses are designed to last 10 years, but the materials could wear out as quickly as five years for folks who are heavier.

What are different companies’ mattress weight limits?

Weight limits vary from brand to brand, as do the consequences of exceeding them. For example, Purple lists a weight limit of 600 pounds, or 300 per person, for its namesake bed, the Purple mattress. The company treats this as a suggestion rather than a hard-and-fast rule, stating: “Exceeding this recommendation will not void the 10-year warranty, and you will still enjoy plenty of the benefits Purple has to offer.”

But that’s not the case with other beds from popular brands. The Cocoon Chill by Sealy has an advertised weight limit of 500 pounds. The company’s page on the subject only reads: “Your Cocoon by Sealy mattress can support up to 500 pounds.”

Nectar doesn’t even mention a weight maximum on its warranty description or on its pages for products such as its Nectar mattress. There is, however, a blog post on the subject that states: “A Nectar mattress can comfortably support up to 650 pounds with no discernable loss of comfort or support.” The company doesn’t make it clear if exceeding that recommendation would negate the warranty.

Casper’s policy is even more lax for beds like its Casper Original. According to the website: “Casper mattresses do not have a weight limit and are designed to support all shapes and sizes.” For what it’s worth, Golub casts doubt on companies that don’t share mattress weight limit recommendations, given that materials tend to degrade from pressure over time.

There are also brands that are known for higher-than-average weight limits. According to Big Fig, its bed was designed to support two sleepers up to 1,100 pounds, or 550 pounds each. The bed uses a high-density foam and extra-supportive coils meant to withstand higher weights and have longevity, Brown says.

What makes materials better or worse at supporting weight?

Foam and coils are the most common mattress materials. They can be used separately, and they’re also often combined to make what’s called a hybrid mattress.

When you get into the nitty gritty, foam is generally considered less supportive than coils—however, this depends on the structure of the foam, as well as the manufacturing process.

Heavier folks should consider inquiring about the specifications of foams when they shop. Some companies, like Saatva, have this information available online. (Though you may have to dig a little—we found it after searching the company’s FAQ page.)

Saatva describes the firmness of its foams using an “ILD” measure, an acronym for “impression load deflection.” This is just a standardized measure of how firm foams are. According to Saatva: “It's the amount of pressure needed to indent a 4-inch piece of foam by 25%. The higher the ILD, the firmer the foam.”

You can also assess a foam mattress’ firmness by checking the density of the foam, which relates to the amount of material you put into a foam, Brown says. “More dense materials have more raw material and less air—less dense has more air,” he explains. A denser foam will feel firmer—and have a longer lifespan, he says.

The structure and materials used to produce coils can also affect how well a mattress supports weight, according to Brown. It’s not just the spring’s gauge, or thickness of steel, but also how tightly coiled it is. There aren’t easy ways to assess this, though you could try directly inquiring with customer service.

What do you need to know about purchasing a mattress and weight limits?

It’s impossible to pinpoint exactly which mattress will be best for you. That depends on a range of factors from the sleep position you favor to whether you share your bed with a partner. Then there’s if you prefer a squishy surface or a firm one.

Body weight differences in two partners can also make it difficult to find a mattress that equally suits both people. A firm mattress that’s comfortable and supportive to one partner could feel excessively firm for the other. In this case, a split king might be the best route. A king, after all, is equivalent to two twin beds—split kings are essentially two twin mattresses pushed together, allowing each partner to meet their needs. Some of our favorite mattresses, including the Nectar mattress and Amerisleep AS3 are available in this size selection.

Arguably, a couple could purchase two twin mattresses from different brands, say Saatva and BigFig, and put them together. The main thing to look for, in that case, would be the mattresses’ height. For instance, a twin Tuft & Needle Original is 10 inches tall, while a twin DreamCloud mattress is 14 inches tall, which would make for an unwelcome difference when putting the beds together.

One final note: Check that your base is compatible with your mattress—and that it can support your bed and body weight. “The worst thing you can do is put an inadequate foundation underneath an inexpensive mattress, because that will also make the mattress break down,” Brown says. “That mattress will start to contour to the weak spots in the foundation [or base] and start to degrade … you run the risk of creating issues in areas of the mattress not necessarily even related to your sleep,” he explains.

Both Golub and Brown say that weight limits at their companies aren’t hard and fast rules. It’s difficult to pinpoint an exact amount of wiggle room over weight limits, and how companies that include these specifics in their warranties would even—legally—be able to enforce them. But in the interest of getting your best sleep, try to look for something that works for your body weight.

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Prices were accurate at the time this article was published but may change over time.