Foundations & Box Springs by Size | Twin to Cal King

Which Size Foundation or Box Spring Do You Need?

Your foundation must match your mattress dimensions exactly. A mismatched base creates uneven support, causes premature mattress wear, and can void your mattress warranty. Use the table below to confirm your size:

Size	Dimensions	Best For
Twin	38" x 75"	Kids, guest rooms, bunk beds
Twin XL	38" x 80"	Teens, tall sleepers, split king
Full	54" x 75"	Solo adults, studios, guest rooms
Queen	60" x 80"	Couples, master bedrooms
King	76" x 80"	Spacious master suites, split option
Cal King	72" x 84"	Tall sleepers, narrow rooms

Split Box Springs for Easier Delivery

King and California King foundations can be difficult to maneuver through narrow hallways, staircases, and doorways. A split box spring solves this by dividing the base into two pieces that fit through tight spaces and reassemble on the bed frame. Queen-size split box springs are also available for homes with particularly narrow access. Once assembled, a split foundation performs identically to a single-piece base.

Choosing the Right Profile Height

Every size in our collection is available in low, standard, and high profile options. The right height depends on your bed frame and desired mattress surface height. Compare all three profiles in our foundations by height collection.

Pairing a Foundation with the Right Mattress

Once you have selected your foundation size, make sure you pair it with a compatible mattress. Memory foam and hybrid mattresses work best on rigid foundations, while innerspring mattresses are compatible with both foundations and traditional coil box springs. Browse our mattresses by size to find matching options.