Understanding Mattress Springs: A Complete Guide to Coil Systems

When it comes to choosing the right mattress, one of the most important factors to consider is the type of spring system inside. While memory foam and hybrid mattresses have gained popularity, innerspring mattresses — those with coils or springs — still remain a top choice for many sleepers. But with so many different coil systems out there, how do you know which one is right for you?

Here’s a complete guide to understanding the most common spring systems in mattresses and what makes each one unique.

1. Bonnell Coils

Bonnell coils are the most traditional and widely used coil system in innerspring mattresses. They are hourglass-shaped and connected by a metal grid. Bonnell coils provide sturdy support and are generally more affordable than other types of coils.

• Pros: Affordable, durable, widely available.
• Cons: Can be less flexible, leading to pressure points, and more motion transfer.
• Best for: Budget-conscious buyers or those who prefer a firmer feel.

2. Offset Coils

Offset coils are similar to Bonnell coils but with a more advanced design. These coils are shaped in an "S" curve and are connected at the top and bottom with a hinge that allows them to adjust more easily to body movement. This provides more flexibility and reduces motion transfer.

• Pros: Greater comfort and flexibility than Bonnell coils, better motion isolation.
• Cons: Can be slightly more expensive than Bonnell coils.
• Best for: Sleepers who want more comfort and less disturbance from their partner’s movements.

3. Pocket Springs (Pocketed Coils)

Pocket springs are individually wrapped in fabric, allowing each coil to move independently. This means that they provide targeted support for different areas of the body and can significantly reduce motion transfer between sleeping partners. Pocket springs are often considered the gold standard for innerspring mattresses due to their comfort and customisation.

• Pros: Excellent support, superior motion isolation, better alignment.
• Cons: More expensive, can be heavier.
• Best for: Couples, back sleepers, and people who suffer from back or joint pain.

4. Continuous Coils

Continuous coils are made from a single, long wire that is formed into a series of interconnected coils. This type of system offers a lot of durability and is less likely to sag over time. The connected coil design helps to distribute weight evenly across the mattress.

• Pros: Durable, even weight distribution.
• Cons: May lack the contouring feel that pocket springs offer.
• Best for: Budget-conscious buyers who want long-lasting support.

5. Micro Coils

Micro coils are smaller, finer coils used as a layer within a mattress, often on top of larger coils or foam layers. These provide extra pressure relief and contouring for sleepers.

• Pros: Added comfort, extra cushioning, good for pressure relief.
• Cons: Can be found in higher-end mattresses, increasing the overall price.
• Best for: Side sleepers or people looking for a softer, more luxurious feel.