Choosing the right feel for your sleep position is essential when finding the perfect mattress. If you're a side sleeper, the instant pressure relief of a medium-firm mattress is often recommended — but what if you turn the firmness up a level? Are firm mattresses too hard for side sleepers?
We've tested beds from across the firmness scale to find this year's best mattress for all sleep styles. For the most part, we recommend side sleepers seek a mattress with good cushioning and stable support, which tends to be exemplified by a medium to medium-firm mattress.
However, there are some side sleepers who prefer a firm feel from their mattress. In this guide, we'll explore how side sleepers can choose a firm mattress that isn't too hard, plus some of our favorite options to shop in the upcoming Presidents' Day mattress sales.
What is a firm mattress?
Mattress firmness is rated on a scale of one to 10 and firm mattresses sit at the higher end of that scale. We classify a firm mattress as around 8-9 on the firmness scale, with a 10 indicating an extra firm feel (these tend to be specialist beds.) But numbers aren't always a great descriptor for comfort, so let's dig into what a firm mattress feels like.
Firm mattresses are often characterized by their lack of sink: when you press into the surface, it offers resistance. This translates to excellent support, as your body is held in a straight position rather than sagging into the mattress. Firm mattresses have a more traditional feel, as you lie on top of the bed.
The flip-side is that firm mattresses often lack pressure relief. The cushioning provided by medium and soft mattresses relieves pressure build-up where the body pushes into the surface. Firm mattresses, which lack contouring, can feel hard beneath the shoulder and hips.
We've slept on some of the best firm mattresses and for the most part, we recommend them to back and stomach sleepers, as well as those with certain types of back pain. However, based on your body type and sleep needs, there are times a firm mattress can suit a side sleeper.
What type of mattress should a side sleeper use?
Side sleeping has many benefits — it's often seen as one of the healthiest sleep positions — and the right mattress can help you stay comfortable when lying on your side all night long.
When you lie on your side, your shoulders, hips and knees press into the bed. This can result in pressure build-up. The best mattresses for side sleepers contour to these touch points to relieve pressure, while maintaining support across the spine.
Medium-firm and medium mattresses are often best at balancing both pressure relief and support. Firm mattresses, which have ample support but tend to lag behind on relief, are often too hard for side sleepers.
What should side sleepers look for in a firm mattress?
I spent several weeks sleeping on the Plank Firm Mattress, marketed as the flattest and firmest bed you can buy (learn more in my Plank Firm Mattress review.) I found it hugely comfortable for back and stomach sleeping but if I rolled onto my side, it was simply too firm at the shoulder and hips — I tended to wake up with a dead arm. But if you like to lie on your side and hate feeling smothered by your mattress, here are the features to look for in a firm mattress for side sleepers:
1. Plenty of pressure relief
Most firm mattresses provide some pressure relief — it shouldn't feel like you're lying on a wooden floor, for example. However, this cushioning is often best for back and stomach sleepers, who need only light relief at the hips and lower back. Side sleepers, who press deep into the mattress at the shoulder and hip, need ample cushioning to limit pressure build-up.
For a firm mattress with better pressure relief, look for a design with multiple foam layers (similar to the best memory foam mattresses) or bouncy and responsive springs. A quilted cover can also aid pressure relief, adding some bounce and lift for your shoulders to sink into.
2. Strong support
High quality firm mattresses are often praised for their support, keeping the body lifted from head to toe. Side sleepers might prioritize pressure relief, but support is also necessary to limit back ache.
If a firm mattress is too hard at the shoulders and hips, look for a medium to medium-firm mattress with a sturdy base. The best hybrid mattresses use springs to create responsive support, while memory foam mattresses use dense foam to limit sag.
3. Suitable for your body type
Mattress firmness is subjective, which means it's hard to put an exact number on a feel. This subjectivity is closely related to weight: a mattress that feels medium-firm to a person weighing over 250lbs will typically feel firm to a person under 130lbs.
Firm mattresses are better for side sleepers with heavier builds, who will experience more sink from the hard surface (the best mattresses for heavy people are primarily firm.) If you have an average build of around 130lbs to 250lbs, a medium-firm mattress is best, while lightweight side sleepers weighing under 250lbs should consider a medium to medium-soft mattress.
3 firm to medium-firm mattresses for side sleepers
