A bunkie board is a piece of plywood that’s placed under the mattress. It’s often used with an older box spring, foundation, or platform bed to provide proper support for a foam mattress (which tends to be heavier than a spring mattress).

A box spring looks more like a piece of furniture. It’s around 6” tall and is often used with a spring mattress to provide additional comfort.

If you have a foam mattress, like a Casper, what you’re looking for is a foundation. Foundations are sturdier than box springs and give mattresses with memory foam the right support.

Box springs were originally designed for spring mattresses. Spring mattresses utilize springs to support the body and “push back” on the weight being applied to them, creating pressure points. Box springs help to minimize this effect by providing additional shock absorption.

Bunkie boards (or bunky boards) are typically used to complement an existing setup. Newer mattresses, particularly those with memory foam (like Casper’s), are denser and heavier than spring mattresses. A bunkie board can be used with a box spring or older foundation or platform bed to ensure that it’s able to properly support the weight of a newer foam mattress. The reality, however, is that bunkie boards don’t often last for the life of the mattress.

We spent thousands of hours designing and redesigning every angle of the Casper Foundation. We sat on prototypes, rolled around on them, and tested them for durability. Russell Jelinek, the lead engineer on the Casper Foundation, specially designed the brackets that hold the foundation together so they’re super durable and easy to use. The whole foundation can be put together in under 10 minutes. In the end, it matches your Casper mattress like an exhausted body falls into bed.