Best Budget Mattress UK (Under £400 Guide)

There is a large gap between the cheapest mattress on the market and a quality budget option that will give you comfortable, supported sleep for several years. This guide explains where that line sits, what you should not compromise on even at lower prices, and what you can reasonably trade off to keep the cost down.

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Is this guide for you?

  • You need a new mattress but have a firm upper limit on what you can spend
  • You are furnishing a guest room or a child's room and want good value
  • You are unconvinced you need to spend over £500 and want to understand why
  • You want to know which budget options are genuinely usable long-term

How the matching quiz works

  1. Answer a few quick questions about how you sleep
  2. We match against mattresses verified on UK Amazon, scoring on fit, temperature and budget
  3. Get a shortlist with reasons — not a single pushed product

What you can and cannot get at budget price points

A budget mattress (under £300–400 for a double) will typically have a lower foam density, a lower spring count, a thinner comfort layer, or some combination of these. The gap in performance compared to mid-range mattresses is real, but it is also manageable if you know what to prioritise.

What to prioritise at budget price points

Some properties matter more than others when the budget is limited.

Avoid open-coil springs

Open-coil (or Bonnell spring) mattresses are the cheapest to produce. All springs are connected, so movement transfers across the whole surface and pressure relief is uneven. Even at budget prices, a pocket-sprung option is a meaningful step up. Some manufacturers produce budget pocket-sprung mattresses at similar price points.

Check foam density if buying foam

The difference between a 25 kg/m³ foam mattress and a 35 kg/m³ one is mostly felt after 18 months when the cheaper version has started to sag. If the density is not stated in the specification, ask before buying.

Prioritise the right firmness over features

A budget mattress in the right firmness for your position and weight will outperform an expensive mattress in the wrong firmness. Get this right first, then work within your price range.

Where budget mattresses cut corners (and whether it matters)

At lower price points, manufacturers typically reduce spring count, foam density, comfort layer depth, cover quality, and edge support. Of these, foam density and spring count matter most for long-term support. Cover quality and edge support matter less for solo sleepers who do not sit on the edge; they matter more for couples or heavier sleepers.

Guest room vs everyday use

A budget mattress used a few nights a month in a guest room can last 10+ years. The same mattress used every night by two adults may show wear within 3–4 years. Matching the specification to the actual usage pattern is more important than price. For a master bedroom used every night, the mid-range (£400–700) is often worth the step up.

Getting value from the UK market

UK retailers regularly run substantial discounts — 30–50% off listed prices. These are often permanent promotional prices rather than genuine reductions. Comparing mattresses at their discounted price gives a more accurate picture of the actual market. Look for manufacturers with transparent pricing, a reasonable trial period (60 nights minimum), and a clear returns process.

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What our quiz looks at

  • How often the mattress will be used (guest room vs every night)
  • Your weight and sleep position — affects how quickly budget foams compress
  • Spring type: pocket springs are worth paying a small premium for even at budget prices
  • Foam density if buying foam-based: 35 kg/m³ or above for everyday use
  • Trial period and returns policy

Frequently asked questions

How much should I spend on a mattress?

For a mattress used every night as a primary bed, £350–600 for a double gets you into the range where quality pocket springs and reasonable foam density are achievable. Below £250, the most common issue is foam that compresses too quickly. Above £700, diminishing returns set in for most sleepers.

Are cheap mattresses bad for your back?

A cheap mattress that provides the right firmness and holds its shape is not inherently bad for your back. The main risk with very cheap mattresses is loss of support over time as low-density foam develops body impressions. Poor support that develops gradually is easy to miss until back pain arrives.

Is a memory foam mattress cheaper than a spring mattress?

At entry level, foam-only mattresses are often cheaper to produce than pocket-sprung options. However, very cheap foam is also lower density and wears out faster. A budget pocket-sprung mattress often provides better long-term value than the same-priced foam option.

Can I get a decent mattress for under £300?

Yes, for light use or a guest room. For a primary bed used every night by an adult of average weight, the £300–400 range is a more realistic minimum for a mattress that will hold up for 5+ years.

Last reviewed: 4 May 2026. We update this guide whenever our verified UK product list changes.