Are soft mattresses supportive or are they bad news for your back?

A woman with dark hair sleeps on a memory foam mattress dressed with white pillows and sheets
(Image credit: Getty)

The best mattresses will offer a keen balance of pressure relief and cushioning support, while cradling the spine in correct alignment. When it comes to keeping back pain at bay, adequate support from your mattress is crucial. 

But for those of us who prefer a soft sleep surface, you might be wondering — can a soft mattress ever be supportive, or are they only ever bad news for your back? The good news is that a mattress can be both soft and supportive, provided that the mattress contains enough supportive layers. 

When shopping for a soft yet supportive bed, the best mattress will be one that works in tandem with your body type, sleep style and sleep needs. Here, we’ll walk you through how to choose a soft and supportive mattress. Let’s get started. 

Is a soft mattress supportive enough? 

Soft mattresses aren’t renowned for their supportive benefits, but a mattress can be both soft and supportive. Similarly, a mattress can be both firm yet unsupportive. The amount of support a mattress provides depends on how many supportive layers it contains. 

Firmness is subjective and your body type and sleep style will influence how soft or firm a mattress will feel to you. However, a firmness rating of 4 or 5 out of 10 is widely considered to be soft. Meanwhile a rating of 2 or 3 out of 10 is widely referred to as marshmallow soft, which means that it’s plush with noticeable sinkage.

Saatva Classic Mattress

(Image credit: Saatva)

A mattress with a soft firmness rating doesn’t necessarily mean that it’s unsupportive. The Saatva Classic, which we deem to be the best mattress in the world (you can read why in our Saatva Classic mattress review), contains five distinctive supportive layers and is available in three different firmness levels, including Plush Soft. 

Saatva rates the Plush Soft as a 3 out of 10 for firmness. Despite its soft firmness rating, the Saatva Classic remains one of the best mattresses for back pain, thanks to its supportive combination of coils and pressure relieving foam.

Which sleep style suits a softer mattress?  

When it comes to how firm your mattress should be, it depends on your sleep style. Back sleep and stomach sleepers suit a medium to medium-firm mattress, as this firmness rating strikes a balance between comfort, pressure relief and healthy spine alignment. Meanwhile, side sleepers benefit from the sink-in, pressure-relieving support that a soft or plush mattress provides. 

However, your body type also plays a large role in which firmness rating you should opt for. Lightweight sleepers (those who weigh under 150lbs) will find medium-firm and firm beds to be much harder than people who weigh 150lbs or more. In this case, a lighter than average back sleeper may require a softer mattress in order to gain adequate support. 

Similarly, a person who weighs over 250lbs will find a medium-firm mattress much softer than a person of average body weight. In which case, searching through the best firm mattresses will garner the medium firmness they're seeking. 

How to make your hard mattress softer  

While mattresses soften naturally over time, that could also indicate that its support is beginning to wane — and this is bad news for your back. However, if your mattress is relatively new and it's firmer than you find comfortable, it is possible to make it feel softer. 

A woman lifts the edge of her white mattress topper placed on top of a white mattress

(Image credit: Getty Images)

The best mattress toppers can alter the firmness of your mattress, helping to make hard mattresses feel soft. A plush mattress topper with a depth of around 4 inches will provide the pillowy sink-in support that your current sleep set-up is lacking.

A bed topper made of feathers or memory foam will also offer soft, comforting support that that will cradle your body and gently relieves pressure points. 

However, it’s also worth checking your thermostat in your bedroom, as a colder room can make your mattress feel firmer. Add some warmth to your bed with a heated blanket or hot water bottle if you’re unable to turn up your home’s heating. You can use a heated blanket with a memory foam mattress as long as you don't place the blanket directly onto the foam or leave it on all night.

3 soft but supportive mattresses to shop today

Saatva Classic mattress: $1,295$1,195 at Saatva

Saatva Classic mattress: from $1,295 $1,195 at Saatva
The Saatva Classic tops our best mattress guide, thanks to its outstanding build quality and customizable support. As well as a Luxury Firm and Firm, the Classic is available in a Plush Soft, which Saatva rates as a 3 out of 10 for firmness. However, you will still glean all the supportive benefits that Saatva are renowned for, like the lumbar memory foam crown that provides outstanding pressie relief across the spine. Saatva also offers some of the best benefits in the industry, with a 365 night sleep trial, lifetime warranty and free White Glove Delivery. 

Helix Midnight Luxe: $1,373$1,099 at Helix

Helix Midnight Luxe: From $1,373 $1,099 at Helix
The official firmness rating from Helix for the Midnight Luxe is 5-6 out of 10, but its ultra soft Pillow Top cover gives it a sumptuously soft cloud-like sleep surface without sacrificing any support . This mattress boasts excellent motion isolation, plus it also comes with the option to upgrade to a GlacioTex cooling cover. 

WinkBed mattress: $1,149$849 at WinkBed

WinkBed mattress: From $1,149 $849 at WinkBed
Like the Saatva Classic, the WinkBed mattress offers customizable support, and is available in a soft, which we rate as a 4.5 out of 10 for firmness. Again, the WinkBed mattress provides outstanding support alongside sink-in cushioning that will appeal to those seeking a softer sleep surface. An evergreen $300 off sale brings the price of a queen size WinkBed mattress down to $1,499. 

Nicola Appleton
Sleep Features Editor

Nicola Appleton is Sleep Features Editor at Tom’s Guide, specialising in quality news content surrounding sleep and wellbeing. Nicola cut her teeth as a journalist in a busy newsroom in Bristol, UK, 15 years ago as part of a team at Britain's largest independent press agency. Since then, her job as a journalist has taken her to the States, to Sydney, and then back to Blighty, where she has written and edited features for a whole host of prominent British and international brands, including  The Independent, The Sydney Morning Herald, HuffPost, Refinery29, Stylist and more. As well as tackling the vast topic of sleep, Nicola will be joining the raft of expert mattress reviewers at Tom's Guide, helping steer readers towards the very best mattresses on the market.