A crib is the piece of furniture that your little one will use the most for the next few years. Crib mattresses are government regulated to ensure a safe environment for your little one, so it is important to select a mattress within these dimensions. To help determine the best sleeping experience for your baby (and you!), follow our guide to pick the correct crib mattress size.

Standard Crib Mattress Size

The standard crib mattress size is 52" L x 27". The mattress is typically 5" – 6" thick and should not be thicker than 6". They are designed to fit snugly inside USA-standard full cribs, which have dimensions averaging within 5/8" of 52" L x 28" W. There should be no gaps larger than two fingers wide between the mattress and the crib.

Mini Crib Mattress Size

Mini or portable cribs are more cost-conscious and work well in tight spaces. The standard mattress size for a mini crib is 38" L x 24" W. The thickness tends to be lower, around 3" – 4" high and no higher than 5". Just like a standard crib, the gaps between the crib mattress and the sides of the crib should be no more than two fingers wide.

Tip!

Keep mattress weight in mind while shopping, since you will most likely be lifting or moving a crib mattress often to wipe it down or change the sheets. Mattresses that weigh more than 20 lbs. can be difficult to maneuver.