Mattress Firmness Quiz: Soft, Medium or Firm?
Choosing the right mattress firmness can make a big difference to how well you sleep. This short quiz asks practical questions about your build, sleep position and comfort needs to suggest whether soft, medium or firm suits you best.
Answer honestly and we'll show matching mattress types along with specific product suggestions from brands such as Maxitex, Noomi, Recoil and Solace+Co.
Why mattress firmness matters
Firmness affects how well your spine stays aligned overnight. Too soft and heavier areas sink, curving the back. Too firm and pressure builds at shoulders and hips. UK mattress sizes such as double 135x190cm (4ft6) or king 150x200cm (5ft) all come in different firmness levels, so the same rules apply regardless of size.
Sleep position and firmness
Side sleepers usually need softer surfaces so the shoulder and hip can sink enough for neutral spine alignment. Back sleepers benefit from medium support that cradles the lumbar curve. Stomach sleepers need firmer mattresses to stop the hips dipping and straining the lower back. These are general rules; body weight also changes the feel.
Body weight considerations
Lighter people (under 60kg) often need softer mattresses because they do not compress foam or springs as much. Average weight sleepers (60-85kg) usually find medium the most comfortable. Heavier sleepers (over 85kg) require firmer options so the mattress does not bottom out. Always check the maximum mattress depth allowed on bunk beds which must meet BS EN 747 with guard rails at least 16cm above the mattress.
Materials and how they affect firmness
Memory foam tends to feel softer and slower to respond. Pocket sprung units give more bounce and can be firmer overall. Hybrids combine both. Latex is naturally firmer and more responsive. All UK mattresses must meet the Furniture and Furnishings (Fire) (Safety) Regulations 1988 and BS 7177. Cot mattresses are typically 60x120cm while toddler beds use 70x140cm.
Practical checklist before you buy
1. Lie on the mattress in your usual sleep position for at least 10 minutes in the store if possible. 2. Ask a partner to check if your spine looks straight. 3. Consider a mattress protector to keep it clean. 4. Think about whether you need a topper later to adjust firmness slightly. 5. Match the mattress to your bed base – solid, sprung or slatted all change the feel.
When to consider a topper instead
If your current mattress is too firm, a memory-foam or latex topper can soften it without buying a whole new bed. Toppers are also useful on firm bunk beds for children over 6. Check the product pages for exact specifications.
Frequently asked questions
Can I change firmness if I get it wrong?
A mattress topper can soften a firm mattress by 1-2cm of cushioning. Changing from soft to firm is harder and usually needs a full replacement. Always check the maximum depth allowed on your bed frame or bunk bed.
Is firmer always better for bad backs?
Not necessarily. Many people with lower back pain find medium support works best because it allows the hips to settle while supporting the lumbar area. Very firm can create pressure points for side sleepers.
How does a partner's weight affect choice?
If you have very different body weights, a medium to firm hybrid with good isolation helps. One person may need a topper on their side. Test together if possible.
Do children's mattresses follow the same firmness rules?
Children under 6 should not use the top bunk. All bunk beds sold in the UK must meet BS EN 747. Most kids do well on medium firmness mattresses such as those from Maxitex. Cot mattresses are usually 60x120cm.
Related guides
Try our interactive tools: All quizzes & checkers · Mattress finder · Bed finder · Room-fit checker · Firmness selector · Kids' bed finder