Coil Gauge Buyer's Checklist: What to Check In-Store

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Understanding Coil Gauge

Coil gauge is one of those mattress specifications that sounds technical but is actually straightforward once you understand the numbering system. It measures the diameter of the steel wire used to form each coil or spring inside the mattress. The gauge directly affects how firm or soft the mattress feels and how long it will last.

The gauge system uses the American Wire Gauge (AWG) standard, which is counterintuitive at first: lower numbers mean thicker wire. A 12-gauge coil is made from thick, strong wire that provides firm support. A 15-gauge coil uses thinner wire that yields more easily to body pressure. Most mattress coils fall between 12 and 16 gauge.

Brad, our senior consultant, uses a simple comparison. "Think of it like spaghetti versus linguine," he says. "Thin spaghetti bends easily. Thick linguine holds its shape. Coil gauge works the same way. Thicker wire means firmer support. It is one of the easiest specs to understand once someone explains it."

Gauge Numbers Explained

Here is a practical breakdown of common coil gauges and what they mean for your sleep experience.

Zoned Gauge Systems

Many modern mattresses use different gauges in different zones of the same mattress. The centre third (under the hips and lower back) uses thicker gauge wire for firmer support where body weight concentrates. The head and foot zones use thinner gauge wire for softer contouring around shoulders and ankles. This zoned approach provides targeted support without making the entire mattress uniformly firm.

Our Restonic Luxury Silk and Wool uses 884 zoned coils with this approach, providing firmer support through the lumbar zone while allowing more give at the shoulders and feet.

Coil Types and How Gauge Applies

Bonnell Coils

The oldest and simplest coil design. Bonnell coils are hourglass-shaped and interconnected with helical wires. They typically use 13 to 14 gauge wire. Because they are connected, pressing on one area affects the surrounding coils, which creates more motion transfer. Bonnell coils are most common in budget mattresses.

Offset Coils

Similar to Bonnell coils but with a flattened top and bottom that creates a hinge effect. This design allows the coil to conform more closely to body contours while maintaining firm support. Offset coils typically use 13 to 14.5 gauge wire and are found in mid-range to premium innerspring mattresses.

Individually Wrapped (Pocketed) Coils

Each coil is encased in its own fabric pocket, allowing it to move independently. This is the gold standard for motion isolation, since pressing one coil does not affect its neighbours. Pocketed coils typically use 14 to 16 gauge wire because they work through collective response rather than individual stiffness. The higher coil counts in pocketed systems (800 to 1,400+ coils in a queen) compensate for the thinner wire.

Continuous Coils

Made from a single continuous wire shaped into hundreds of connected coils. Continuous coil systems typically use 13 to 14 gauge wire and are known for durability. They provide consistent support but transfer more motion than individually wrapped coils.

Your In-Store Coil Gauge Checklist

When you visit a mattress showroom, knowing what to ask puts you in control of the conversation. Here is what to check about coils and gauge during your visit.

What to Feel When Lying Down

Specifications matter, but your body is the final judge. Lie on the mattress in your typical sleep position for at least five minutes. Pay attention to whether your spine feels aligned, whether your hips sink too deeply or sit too high, and whether you feel pressure points at your shoulders or knees.

Dorothy, our sleep specialist, guides every customer through this process. "The numbers give you a baseline, but your body tells you the truth," she says. "Two mattresses with identical coil specs can feel very different because of the comfort layers on top. Start with the specs to narrow your options, then let your body make the final decision."

Coil Gauge and Body Weight

Your body weight should influence which coil gauge range you consider. Heavier individuals need thicker gauge coils to prevent excessive sinking, while lighter individuals may find thick gauge coils uncomfortably firm.

These are general guidelines. Sleeping position also matters. Side sleepers need slightly softer coils at the shoulders regardless of body weight, while back sleepers benefit from firmer support through the lumbar zone.