How open coil springs work#

An open coil mattress (also called a continuous coil or Bonnell coil) uses a network of interconnected springs throughout the mattress. When one spring moves, surrounding springs move with it. This system is inexpensive to manufacture, which is why open coil mattresses are typically the cheapest spring mattresses available.

Open coil mattresses are found primarily at the budget end of the market (under £200 for a double), in some budget hotel chains and in children's beds. They are a reasonable short-term solution but are not recommended for primary adult use due to their relatively poor support and shorter lifespan.

How pocket springs work#

A pocket sprung mattress contains individual springs, each housed in its own fabric pocket. Each spring moves independently — when you press down on one spring, the adjacent springs are barely affected. This independent movement is the defining advantage of pocket sprung mattresses.

The number of springs in a double mattress typically ranges from 800 to 3,000+. This is heavily marketed by manufacturers, but the quality of the spring steel, the gauge of the wire and the quality of the comfort layers above the springs are more important than spring count.

Head-to-head comparison#

  • Comfort: Pocket spring wins. Each spring responds to your specific body shape and weight distribution.
  • Support: Pocket spring wins. Better contouring means better spinal alignment for most sleepers.
  • Motion isolation: Pocket spring wins substantially. If you share a bed, your partner's movements won't disturb you as much.
  • Durability: Pocket spring wins. Interconnected coils fatigue faster; individual pocketed springs last longer.
  • Breathability: Both spring types allow good airflow compared to all-foam mattresses. Roughly equal.
  • Price: Open coil wins — they are significantly cheaper. You can buy a decent open coil double for £100–£150; pocket sprung starts from around £200 and quality examples cost £400–£800+.

When to choose open coil#

Open coil mattresses are suitable for: a spare bedroom used infrequently, a child's first mattress, a short-term rental property, or where budget is extremely tight. For primary adult use, we always recommend at least a budget pocket-sprung mattress.

When to choose pocket spring#

Pocket sprung is the better choice for: primary adult use, couples (motion isolation), back or joint pain sufferers (better contouring and support), and anyone who wants a durable mattress that will last 8–12 years. Combine a good pocket sprung base with quality comfort fillings for the best value proposition in the mid-price range.