How big is a crib mattress?

How big is a crib mattress?


When it comes to setting up a nursery for a new baby, one of the essential items to consider is a crib mattress. The size of a crib mattress is crucial for ensuring a safe and comfortable sleep environment for your little one. In this article, we will dive deeper into the topic of crib mattress size, exploring the standard dimensions and variations you may come across.

Standard Crib Mattress Size

Dimensions: The standard size for a crib mattress is 28 inches in width and 52 inches in length. This size is designed to fit most standard cribs perfectly. The thickness of a crib mattress typically ranges from 4 to 6 inches.

Regulations: It is important to note that crib mattress size is regulated to ensure safety standards are met. The Consumer Product Safety Commission (CPSC) in the United States sets guidelines for crib mattress dimensions to prevent gaps between the mattress and the crib’s sides. These regulations aim to reduce the risk of entrapment and suffocation.

Variations in Crib Mattress Size

While the standard crib mattress size is widely accepted, there may be some variations in dimensions depending on the manufacturer or specific crib model. It is essential to measure the crib and the mattress before making a purchase to ensure a proper fit.

Mini Crib Mattress: Mini cribs are a popular choice for smaller spaces or as an alternative to a full-size crib. Mini crib mattresses are generally smaller than standard crib mattresses, measuring around 24 inches in width and 38 inches in length. These mattresses are specifically designed to fit mini cribs and should not be used interchangeably with standard crib mattresses.

Portable Crib Mattress: Portable cribs, also known as travel cribs or playards, often come with their own mattresses. These mattresses are typically thinner and lighter than standard crib mattresses for ease of portability. The dimensions of portable crib mattresses may vary, but they are generally similar to mini crib mattresses.

Custom Crib Mattress: In some cases, you may require a custom-sized crib mattress. This could be due to having a non-standard crib or a unique space constraint. If you need a custom crib mattress, it is recommended to consult with a reputable manufacturer who can create a mattress to your specific dimensions while still adhering to safety guidelines.


Choosing the right size crib mattress is essential for creating a safe and comfortable sleep environment for your baby. While the standard crib mattress size is 28 inches by 52 inches, there may be variations in size depending on the type of crib or specific manufacturer. It is crucial to measure the crib and mattress before making a purchase to ensure a proper fit and compliance with safety regulations.


– Consumer Product Safety Commission:
– American Academy of Pediatrics: