What Is a Coil Mattress? A Complete Australian Guide to Spring Beds

A coil mattress uses steel springs as its main support core, giving it the bouncy, breathable feel that's defined traditional beds for over a century. Even with the rise of foam and hybrids, coil mattresses remain one of the most popular mattress types in Australia — particularly for hot sleepers, couples, and anyone who prefers a firmer, more responsive surface.

A coil mattress uses steel springs as its support core, making it breathable, responsive, and well-suited to hot sleepers, couples, and back/stomach sleepers. Modern pocket spring designs dramatically reduce motion transfer compared to older bonded coil systems, while quality coil mattresses typically last 7–10 years with proper care.

Key Takeaways

• A coil mattress uses steel springs arranged in a support core for bounce, support, and breathability.
• Pocket spring mattresses are the modern premium choice — each coil is individually wrapped, dramatically reducing motion transfer between partners.
• Coils generally suit hot sleepers, back/stomach sleepers, and couples; foam is better for side sleepers and those wanting deep contouring.
• Quality coil mattresses last 7–10 years with proper care.

This guide explains how coil mattresses work, the different types of spring systems, how they compare to foam and hybrids, and who they suit best.

What Are Coil & Spring Mattresses?

A coil mattress (also called a spring or innerspring mattress) is a bed built around a core of metal springs that compress and rebound to support your body. The coils sit between layers of padding — often foam, fibre, or fabric — that provide the comfort surface you actually sleep on.

When you lie down, each coil compresses under your weight and pushes back, creating a responsive, slightly bouncy feel. This is why coil mattresses feel firmer and more "active" than foam beds, which absorb your weight more passively.

A brief history. The first innerspring mattress was patented by German inventor Heinrich Westphal in 1871, using steel coils originally designed for carriage seats. Innerspring beds went on to dominate bedrooms worldwide for the next century, and even with the rise of memory foam in the 1990s and hybrid designs in the 2010s, coils still account for a huge share of mattresses sold globally.

How they differ from foam mattresses. Foam mattresses use one or more layers of memory foam, latex, or polyurethane as their support core — no springs. They feel softer, contour more closely to the body, and isolate motion better. Coils trade some of that contouring for breathability, durability, and bounce.

Types of Coil Systems

Not all coil mattresses are built the same. The spring design changes how the bed feels, how long it lasts, and how well it isolates motion. There are four main types you'll encounter:

• Bonded coils (also called open or Bonnell coils). The original coil design — hourglass-shaped springs interconnected by a mesh of wire. Cheap and durable, but motion travels across the whole bed (so you'll feel a partner roll over) and the support is uniform rather than targeted.

• Offset coils. A variation on bonded coils where each spring is hinged to its neighbours. This allows for more targeted support and better contouring than bonded coils, while still being affordable. A common choice in mid-range mattresses.

• Pocket springs. Each coil is individually wrapped in a fabric pocket, allowing it to move independently. This dramatically reduces motion transfer and lets the mattress conform more closely to your body. The premium choice, and what you'll find in most quality modern coil mattresses.

• Continuous coils. A single piece of wire is twisted into rows of springs. Cheap and durable, but the connected design means motion transfer is high and the support feel is uniform — not as comfortable as offset or pocket designs.
  

Pocket Spring Mattresses Explained

A pocket spring mattress is a coil mattress where each spring is encapsulated in its own fabric pocket, allowing every coil to compress independently. This is the modern, premium evolution of the traditional spring mattress and the design used in most quality coil mattresses today.

Why individual encapsulation matters. When coils are connected (as in bonded or continuous designs), pressing down on one part of the bed pulls the surrounding coils down with it — that's what creates the "ripple effect" you feel when a partner moves. Pocket springs eliminate this because each coil only responds to direct pressure above it.

Motion isolation for couples. Independent mattress testing consistently rates pocket spring mattresses as significantly better at motion isolation than bonded or continuous coil designs, because each coil compresses individually rather than transferring movement across the bed. This is why pocket springs are recommended for light sleepers who share a bed with a restless partner.

Targeted support. Because each spring acts independently, pocket springs contour to your body's shape — softening under heavier pressure points like hips and shoulders, while staying firmer under your lower back and legs. This produces better spinal alignment than uniform-coil designs.

Durability. Quality pocket spring mattresses typically last 7–10 years, with the individual encasement protecting coils from rusting and sagging. The fabric pockets also stop coils from squeaking against each other over time.

Why they're the premium option. Pocket springs are more complex (and more expensive) to manufacture, with hundreds or thousands of individually wrapped coils per mattress. The trade-off is significantly better comfort, motion isolation, and longevity than cheaper coil designs.

Most Koala adult mattresses use all-foam construction rather than pocket springs — if you want the bounce and breathability of pocket springs without the limitations (squeak over time, motion transfer in budget designs), Koala's Kloudcell® foam mattresses offer similar responsiveness with better motion isolation.

What Coil Gauge and Coil Count Do You Need? 

Two main factors determine how firm a coil mattress feels and how well it supports your body: coil gauge (the thickness of the wire) and coil count (how many springs are in the mattress).

Coil gauge. Coil gauge measures the thickness of the wire used to make each spring. The coil gauge scale runs from 12 (thickest, firmest) to 15 (thinnest, softest), so lower numbers mean thicker wire. Most quality mattresses use coils between 13 and 15 gauge.

Coil count. Simply the number of springs in the mattress. According to Sleep Foundation industry data, a queen-size mattress typically has between 600 and 1,500 coils, depending on construction. More coils generally mean better support and contouring, but the relationship isn't linear — a well-engineered 800-coil pocket spring mattress can outperform a poorly designed 1,500-coil one.

Does more coils always mean better? No. Past a certain point, adding more coils delivers diminishing returns. What matters more is coil quality, gauge, and zoning (where firmer coils are placed under heavier body areas like hips and lower back).

Support profiles by sleeper. Heavier sleepers and stomach sleepers usually want firmer (lower gauge) coils for proper alignment. Side sleepers benefit from softer (higher gauge) coils that allow their hips and shoulders to sink in slightly. Back sleepers sit in the middle — medium-firm is the sweet spot. For more on matching mattresses to your sleep style, see our best sleeping position guide.

Coil Mattresses vs Foam Mattresses

The choice between coil and foam comes down to feel, support style, and what you prioritise in a bed. Each has clear strengths — and modern open-cell foams (like Koala's Kloudcell®) sit between the two on most measures. 

Bounce and responsiveness. Coils spring back when compressed, giving the bed a lively, supportive feel. Traditional foam absorbs your weight and rebounds slowly, creating a "sinking in" sensation. Modern open-cell foam (like Kloudcell®) responds instantly to movement — closer to the feel of coils but without the squeak.

Pressure relief. Foam, particularly memory foam and open-cell foam (Kloudcell®), conforms more closely to your body and reduces pressure on hips and shoulders better than most coil designs. This is why foam is a frequent recommendation for side sleepers and those with joint pain.

Motion isolation. Foam wins easily — but pocket spring mattresses come close. Bonded and continuous coil mattresses are the worst for motion transfer.

Temperature regulation. Coil mattresses sleep cooler than traditional foam because the open spring structure allows air to circulate through the bed. Modern open-cell foams close that gap — Koala's Kloudcell®, for example, is engineered with an open-cell structure designed for breathability and heat dissipation, addressing the main weakness of traditional foam. 

Durability and price. Quality coil mattresses typically last 7–10 years, slightly longer than mid-range traditional foam (6–8 years). Koala's Kloudcell® mattresses come with a 10-year warranty — built-to-last open-cell foam that holds shape and comfort over time. For more on foam construction, see our foam mattress guide.

Coil Mattresses vs Hybrid Mattresses

A hybrid mattress combines a coil support core with thick foam comfort layers on top — typically memory foam, latex, or a blend. Hybrids aim to deliver the best of both worlds: the bounce and breathability of coils with the contouring and pressure relief of foam.

When coils alone are preferred. If you want the firmest, most responsive feel and the best breathability, a pure coil mattress is the right pick. Hybrids will always feel slightly softer because of the foam layer on top.

When hybrids offer the best balance. If you want some contouring without the heat retention of pure foam — particularly if you're a side sleeper who shares a bed — a hybrid is often the smartest choice. Hybrids also tend to outperform pure coil mattresses on pressure relief and motion isolation.

Cost and longevity. Hybrids generally cost more than pure coil mattresses but last about the same time (7–10 years). The foam comfort layers in a hybrid often degrade slightly faster than the coil core, which is why hybrids start to feel different after 5–6 years even when the coils underneath are still solid.

For broader recommendations, see our guide to the best mattress for Australian sleepers.

Who Should Choose a Coil Mattress?

Coil mattresses suit a wider range of sleepers than people often assume — particularly for Australian climates where breathability is a real factor.

• Back sleepers. Medium-firm pocket spring mattresses provide the lumbar support back sleepers need without going overboard on firmness. The bounce also makes it easier to roll over without sinking in.

• Stomach sleepers. Firmer coils (lower gauge) prevent the lower back from arching uncomfortably. Pocket springs or offset coils with a thinner comfort layer work best.

• Hot sleepers. Coils win this category easily. The open structure between springs allows heat and moisture to escape, making coil mattresses noticeably cooler than foam, especially during humid Australian summers. If you're after the best of both worlds — cooling performance with the motion isolation of foam — the Koala Polar+ Mattress uses PolarBands™ technology to sleep 5°C cooler than the standard Plus, without the noise or motion transfer of coils.

• Couples. Pocket spring mattresses minimise motion transfer between partners. If your partner is a thrasher or works shifts, a quality pocket spring is one of the best options outside pure foam.

• People who like bounce. If you've ever felt "stuck" in a memory foam bed, you'll appreciate the responsive feel of coils. They make changing positions, sitting up to read, or getting out of bed feel effortless.

• Budget-conscious buyers. Bonded or continuous coil mattresses are some of the most affordable options on the market. Not the most refined feel, but reliable support at a low price.

When coils may not be the right choice:

• Side sleepers needing deep pressure relief — foam or hybrid is usually better
• Light sleepers sharing a bed with a thrashing partner — pocket spring helps, but foam or hybrid is the gold standard
• People who actively want a "sinking in" feel rather than support and bounce

For side sleepers or those wanting deeper pressure relief, the Koala SE Mattress or Koala Luxe Mattress are worth exploring as foam alternatives.

Coil Mattress Durability & Care

A quality coil mattress lasts longer than most foam alternatives, but lifespan still depends on care. With proper maintenance, you can comfortably get 7–10 years of supportive sleep out of one. According to NapLab's mattress lifespan analysis, quality pocket spring mattresses typically last 7–10 years with proper care, with premium options often lasting longer.

Expected lifespan. Pocket spring mattresses typically last 7–10 years before showing signs of wear. Bonded coil mattresses often degrade faster (5–8 years) because the connected wire structure stresses individual coils more.

Common wear patterns. Coil mattresses tend to develop visible body indentations or sagging in the most-used spots before the coils themselves fail. Edge support also weakens over time, making the perimeter of the bed less stable.

Maintenance to extend life:

• Rotate every 3 months. Turn the mattress 180° to even out wear (most modern coil mattresses can't be flipped, only rotated)
• Use a quality bed base. A solid, slatted, or sprung base prevents premature coil sagging
• Use a mattress protector. Blocks sweat, oils, and dust from reaching the coils and surrounding padding
• Vacuum periodically. Removes dust, skin cells, and allergens that build up in the surface layers
• Don't sit on the same edge daily. Edge coils compress faster than centre coils

When coils fail vs foam breakdown. Coil failure typically shows up as visible sagging, pokey springs, or a noticeably louder squeak when you move. Foam degradation tends to be more gradual — slow loss of support without obvious surface signs. If your coil mattress has a clear dip or you can feel a spring poking through, replacement is overdue.

For a deeper guide to mattress hygiene, see how to clean a mattress for step-by-step instructions.

Considering an all-foam alternative?

Koala's mattresses use Kloudcell® open-cell foam — designed to deliver the responsive support of springs and the contouring of memory foam, without either's drawbacks. Every Koala mattress comes with a 120-night sleep trial and a 10-year warranty, so you can test it properly before committing.

Explore the range →