What Makes a Good Mattress? A No-Nonsense Buying Guide

A mattress is one of the most important purchases you will make for your health, yet the industry is notorious for confusing terminology, inflated claims, and high-pressure sales tactics. Here is what actually matters when choosing a mattress, based on sleep science rather than marketing.

Firmness Is Personal, Not Universal

Despite what advertisements suggest, there is no single firmness level that works for everyone. The right firmness depends on your body weight, sleeping position, and whether you have any pain conditions. Lighter individuals (under 60kg) generally need a softer mattress that allows adequate contouring at the shoulders and hips. Heavier individuals (over 100kg) typically need firmer support to prevent excessive sinking that causes spinal misalignment. The only way to know is to test a mattress for at least a week, which is why generous trial periods matter more than showroom impressions.

Support Versus Comfort: Two Different Jobs

A common misconception is that a mattress should feel soft to be comfortable. In reality, a mattress has two distinct functions. The support system — typically innersprings or high-density foam — maintains spinal alignment by distributing your body weight evenly. The comfort layer — softer foam, latex, or fibre on top — provides pressure relief at contact points like shoulders and hips. A good mattress gets both right: firm enough to support, soft enough to cushion.

Innerspring, Foam, Latex or Hybrid

Innerspring mattresses offer the most traditional feel with good airflow and responsive support. Individually pocketed coils are superior to connected coils because they move independently, reducing motion transfer from a sleeping partner. All-foam mattresses provide excellent pressure relief and motion isolation but can sleep hot without cooling technology. Natural latex offers a resilient, breathable option that resists body impressions well over time. Hybrid mattresses combine pocketed coils with foam or latex comfort layers, aiming to offer the benefits of both.

What to Ignore When Shopping

Certain marketing claims are essentially meaningless. Orthopaedic and medically approved carry no standardised definition. Thread count on mattress covers has minimal impact on sleep quality. The number of coils matters less than their quality and configuration. Pillow-top surfaces may feel luxurious in the showroom but can compress and develop body impressions more quickly than integrated comfort layers. Focus instead on the quality of materials, the density of foams, and the construction methods used.

When to Replace Your Mattress

Most mattresses have a functional lifespan of seven to ten years, though high-quality latex can last longer. Signs that your mattress needs replacing include visible sagging or body impressions deeper than 3 centimetres, waking with stiffness that resolves after moving around, sleeping better in hotels or other beds, and increased allergy symptoms from dust mite accumulation. If your mattress is over eight years old and you are not sleeping well, replacing it is one of the highest-return investments you can make in your health.