Available 
Komfi GelMed Ortho Mattress
from £645-£1,019.
£645-£1,019
Sizes tracked: Single, Double, King Size, Super King
Sleep guide
How often should you replace a mattress?
Mattress Online suggests replacing a mattress every seven years, but the smarter move is to judge comfort, support and fit before you buy again.
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Last verified: 2026-06-23
How long a mattress usually lasts
Mattress Online’s advice uses seven years as a practical guideline, not a fixed deadline, because lifespan depends on mattress type and how much wear it has had. That matters if you are comparing an orthopaedic model like the Komfi GelMed Ortho Mattress, a hybrid such as the Luna 4000 Support Gel Memory Pocket Hybrid Mattress, or a pocket-sprung option like the Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress. If your current mattress is still supporting you properly, a later replacement may be fine; if comfort has dropped off earlier, an upgrade can make more sense than waiting for the calendar to catch up.
Signs your mattress needs replacing
The most useful checks are practical: sagging, dips, lumps, loss of support, noisy springs, and waking up feeling less rested than you used to. Mattress Online also frames replacement around comfort, support, hygiene and sleep quality, so visible wear is only part of the picture. If a mattress now feels uneven or too soft in the middle, that is a stronger buying cue than the age alone, especially when the replacement is a firmer-feel option like Komfi GelMed Ortho or Silentnight UltraGel 3000.
What changes with age
Over time, comfort layers can compress, support can feel less even, and the mattress can become less fresh for everyday use. That is why the retailer’s advice links replacement to comfort, support, hygiene and sleep quality rather than just appearance. Construction matters too: a hybrid like Luna 4000 combines sprung support with a foam comfort layer, while a pocket-sprung mattress and an orthopaedic design may age differently depending on how they are built and rotated.
When to replace sooner
Some shoppers should replace earlier than seven years if the mattress gets heavy use, the bed has been damaged, or household needs have changed. Body changes and allergy or hygiene concerns can also make an older mattress feel less suitable, even if it has not reached the usual guideline age. The safe approach is to focus on comfort and support, then check the retailer page for the latest size, firmness and depth details before choosing a new mattress.
How to choose a replacement
Start with sleep position and firmness labels, then check temperature comfort, size availability and bed-frame compatibility before comparing prices. Mattress Online’s product pages show that depth can affect bedding and bed-frame fit, which is worth checking on the Komfi, Luna and Silentnight listings before you choose a size. If you want a firmer feel, the Komfi GelMed Ortho Mattress and Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress sit in that lane, while the Luna hybrid is the lower-priced entry point at £389 to £799.
What the retailer and product pages suggest
The shortlist is useful because it gives you three different construction routes to compare: orthopaedic, hybrid and pocket sprung. That matters when you are deciding whether to replace now for better support or to move into a different mattress style altogether. Mattress Online also offers a 100-night comfort trial on these mattresses, which is helpful reassurance if you are upgrading for a firmer feel or different comfort layer, but the visible ratings should be treated cautiously because review-count totals are not provided here. Price-wise, Luna starts lower at £389 to £799, while Komfi and Silentnight sit higher at £645 to £1,019 and £645 to £1,029 respectively.
How to turn the advice into a shortlist
If you are replacing on a budget, the Luna 4000 Support Gel Memory Pocket Hybrid Mattress is the lowest starting price in this set and may suit shoppers who want sprung support with a cooler-feel foam layer. If your main concern is firmer support, Komfi GelMed Ortho and Silentnight UltraGel 3000 are the more direct matches, but check the latest retailer price, size availability and mattress depth because both sit in the mid-to-premium range. The trial and guarantee details are useful reassurance, yet they do not prove long-term performance, so compare the construction, firmness label and bed-frame fit before you decide.
Mattresses to use as comparison examples
Available 
Luna 4000 Support Gel Memory Pocket Hybrid Mattress
from £389-£799.
£389-£799
Sizes tracked: Single, Small Double, Double, King Size, Super King
Available 
Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress
from £645-£1,029.
£645-£1,029
Sizes tracked: Single, Small Double, Double, King Size, Super King
Retailer details used
Last checked 2026-06-23. The source list below is included to help you check the details behind the comparison. Always confirm the latest price, delivery cost, stock status and product details with the retailer before buying.
- Komfi GelMed Ortho Mattress | Mattress Onlineproduct-page evidence for Komfi GelMed Ortho Mattress
- Luna 4000 Support Gel Memory Pocket Hybrid Mattress | Mattress Onlineproduct-page evidence for Luna 4000 Support Gel Memory Pocket Hybrid Mattress
- Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress | Mattress Onlineproduct-page evidence for Silentnight UltraGel 3000 Mirapocket Box Top Firmer Mattress
- How Often Should I Change my Mattress? | Mattress OnlineReplacement timeline, signs of wear, hygiene/support rationale
- How Often Should I Rotate or Turn My Mattress? | Mattress OnlineRotation frequency and wear-distribution guidance
- Mattress Online 100 Night Comfort Trial | Mattress OnlineTrial-period context and delivery/collection of replacement mattress
Helpful next reads
Use these related mattresses guides and reviews to turn the advice into a practical shortlist.
Firmness questions
How long should I keep a mattress before replacing it?
Mattress Online recommends replacing a mattress every seven years as a guide, but usage and mattress type matter. If comfort or support fades earlier, it can make sense to replace sooner.
What signs mean I should replace a mattress sooner?
Look for sagging, lumps, dips, noisy springs, reduced support or mornings when the bed feels less comfortable than before. If you are waking up less rested, that is a useful cue to compare replacements.
Should I choose by firmness or sleep position when replacing a mattress?
Use both. Firmness labels help you narrow the feel, while sleep position and bed-frame compatibility help you avoid a poor fit. For example, the Komfi and Silentnight options lean firmer, while Luna sits as the lower-priced hybrid.
Does mattress type change replacement timing?
Yes. The seven-year rule is only a guideline because wear depends on construction and use. An orthopaedic, hybrid or pocket-sprung mattress may age differently, so compare the product page details rather than relying on age alone.