February 2022

One side firm, one side soft; split tension mattresses explained

Split or dual tension mattresses (also called "half and half mattresses") offer a perfect solution for two different weighted sleepers. They can allow for one-half to be one tension, and the other side to be a different tension. This removes the need to fight for your preferred mattress tension with your other half! You really can have your cake and eat it. We explain why split tension beds can help you sleep better.

Updated 2022: If you and your partner struggle to agree on the perfect mattress it may be because you need a dual mattress that allows each of you to have your own custom pocket spring support. A half and half mattress could be the answer you’ve been waiting for!

Pocket spring half and half mattress stitching
Split tensions could be the answer to your sleep problems

This article will explain how you can have two different spring tensions in a mattress.

What is a split mattress?

Split mattresses for couples can help both you and your partner to sleep better by creating a custom mattress based on your body weights and sleeping preferences. A split mattress uses two different pocket spring tensions. This means you can customise support based on your body weight.

Dual tensions can also reduce the disturbance caused when your sleeping partner moves in the night. This is because there is less chance of fidgeting due to being uncomfortable. It leads to a far better night’s sleep!

Sleeping couple On John Ryan By Design Split Tension Mattress

Split Mattresses for Couples Explained:

More often than not, mattress retailers only offer you one tension in a mattress, meaning that (usually) one partner is having to make a sleep compromise. So if one sleeper is 9 stone and the other is 16 stone, retailers make you choose between a soft 1.2 gauge spring or a firm 1.6 gauge spring, so one sleeper is always missing out.

However, split tension mattresses can give you both the perfect support even if you have different mattress preferences.

These split mattresses for couples are available in King size and above.

We don’t believe in compromise when it comes to sleep. So a dual tension can enable you both to have a fantastic mattress leading to better sleep.

A "d link" mattress on a base

What is a Split/dual tension mattress?

A dual or split tension mattress allows you to have two different spring tensions in a one-piece mattress. This is ideal for sleepers of different weights that may need a different spring tension each.

So if you need a medium mattress and your partner’s bodyweight requires a firm mattress, then a split mattress can offer you both the correct spring tension.

Half firm half soft mattresses

A half soft half firm mattress is available in a zip and link model where the mattress is made from two independent halves that then are seamlessly zipped together. If you require a soft spring and your partner a firm spring, then this is the perfect solution for you!

A zip and link mattress by John Ryan By design

If you and your partner have ever struggled to agree on a mattress due to having different sleeping preferences, then a dual tension mattress can provide the perfect solution.

A split tension can vastly improve sleep for both partners
A split tension can vastly improve sleep for both partners
Meaning no more compromises with your mattress choice
Meaning no more compromises with your mattress choice

What spring tension should I pick for my mattress?

We have discussed how the spring tension alone is not the deciding factor in how soft, medium or firm a mattress will feel. In the majority of instances, the upholstery (alongside the spring gauge) dictates the comfort feel. However, spring tensions are made with weight tolerances in mind, and there is a helpful table below to get you started on which tension to look at.

Artisan Spring TensionWeight Range
SoftAvailable as a Bespoke Product (Please Call)
MediumUpto 16 stone / 101kg
FirmOver 16 stone / 101kg

What mattress sizes are split/dual tension beds available in?

Split tension mattresses are available in kingsize bed sizes and above. Smaller sized mattresses are only available in one spring tension, which is probably why a double-sized mattress is now less popular than a King size mattress here in the UK.

It’s important that you choose the correct spring tension based on your body weight and not mattress comfort. The comfort is provided by the upholstery, not the pocket spring unit.

Bed and mattress sizes UK

What are the different mattress tensions for a dual mattress?

Split tensions are available in either:

  • Soft & Medium Split
  • Medium & Firm Split

For example: if you’re an 8 stone sleeper but your partner is 14 stone, you would need a Soft & Medium split. If you went for a retailer’s one-piece mattress, the 8 stone sleeper would either be on a painfully-firm support unit or the 14 stone sleeper would be totally unsupported. With a split tension, you can both be perfectly supported.

The reason a Soft & Firm split is not possible in a one-piece is that it requires perimeter support to bridge the gap between the two different tensions. However, this is possible with a zip and link mattress.

Spring TensionWire diameter (Gauge)Weight Range
Soft1.2mmBespoke Tension (Please Call)
Medium1.4mmUpto 16 stone
Firm1.6mm16 stone plus
Extra Firm / Orthopaedic1.9mm20 stone plus

The other alternative is to opt for a zip and link construction. This can involve having one side with a lower or higher spring count than the other. It can also be constructed with firm plus soft or any other combination of spring tensions.

Calico pocket springs in a soft spring tension

Zip and Link Mattress Tension Sizes

  • Soft & Firm Split (not available in a one-piece)
  • Soft & Medium Split
  • Medium & Firm Split

The mattress can only be flipped (not rotated) without losing your sleeping side, but this is a small sacrifice for two different weighted sleepers. On zip and link models, there are ways to combat this by having the zippers on each side of each individual mattress. However, this method does come at a price to account for the extra labour involved. Read here for all about zip and link mattresses.

Zip & Links reduce transference meaning less disturbance
Zip & Links reduce transference meaning less disturbance
Split tensions mean if you and your partner need different spring tensions, that's not a problem!
Split tensions mean if you and your partner need different spring tensions, that's not a problem!

So why do we need dual spring mattress tensions?

Split tensions are perfect when there is a weight difference between two sleepers, as we have detailed above. Without a split tension then the chances are that one of you will be uncomfortable during the night. We have spoken to plenty of couples who have been mis-sold a one-piece mattress with the wrong spring tension.

Split tension beds are available from high-end mattress manufacturers. You will rarely see dual tension beds in retailers as they are made to order. However, when it comes to sleep you should not compromise simply because these stores don’t stock the correct model for you!

A back sleeper relaxing on a half and half mattress

Spring tensions are based solely on your body weight and should not be confused with ‘Comfort Feel’ of the mattress. The ‘Comfort Feel’ is always provided by the upholstery on top of the spring unit.

So, if you choose the wrong spring tension (i.e. you’re 13 stone and you choose firm) you will really struggle to get comfortable in bed as this spring tension is made for people who weigh 16 stone plus. Dual tension beds allow you both to have the perfect spring tension for your bodyweight.

Artisan pocket spring mattress
You may have been mis-sold the wrong spring tension on your current mattress

If you’re vastly different in weight say 7 stone and an 18 stone sleeper then a zip and link model is more suitable that way you can have completely opposing spring tensions such as Soft on one side and Firm on the other.


To summarise, a split tension or dual spring mattress can allow couples to each get a perfect night’s sleep.

There’s no need to compromise for your other half, as both sleepers can have the perfect spring tension they need in bed.

It’s worth bearing in mind that low-priced mattress models do not have this level of choice of differing spring tensions, and it will only be an available choice within the mid to high-end range from most mattress manufacturers. All of our Artisan mattress range are available with tailored spring tensions for your bodyweight.

If you’re still stuck, why not give our small friendly team a call on 0161 437 4419 for more tailored help.

Don't you deserve a mattress tailored just for you?
Our small friendly team can help you choose a mattress specifically tailored to your needs. With our 60 Day Love it or Return it Guarantee its completely risk-free.

We’re here to help

  • We are the mattress experts! Ask us anything about any mattress by any manufacturer for honest advice and support.

We are here to help
Why not give our small friendly team a call for tailored mattress advice?
0161 437 4419
Based on 2000+ reviews Trustpilot

Ask us a question.

There are over 6000 questions and answers submitted by you on all questions about mattresses and bed problems. Enter a keyword such as Vi Spring, John Lewis beds, bad back or Memory Foam and see if your question has already been answered.

You can filter popular questions by the categories below. If you can’t find an answer, ask a new question below. We aim to respond to all questions within one working day.

Ask a question
Start typing your question below:
John Lewis and Staples Mattresses Reviewed
132962 views 2 answers arrow
Simba mattress and Eve rave reviews?
63396 views 1 answer arrow
Are sprung slats better than rigid slats?
42533 views 2 answers arrow
Problems with I-Gel mattress from Bensons
34353 views 2 answers arrow
No results
Load More Questions