Find Your Baby’s Sleep Sack Size

Baby sleep sack size chart helps parents select the right sleep sack for their baby based on age, weight, and length. Sleep sacks are wearable blankets that ensure the baby stays warm and comfortable during sleep while reducing the risk of suffocation or overheating, unlike loose blankets. Proper sizing is important to ensure the baby is comfortable, safe, and able to move freely without being too restricted.

Baby Sleep Sack Size Chart

SizeAge RangeWeight RangeLength (inches)Recommended Use
Newborn0 - 3 months5 - 12 lbs21 - 23 inchesIdeal for newborns who are just starting to sleep through the night.
Small3 - 6 months12 - 18 lbs23 - 26 inchesSuitable for babies who have started to roll and need room for movement.
Medium6 - 12 months18 - 24 lbs26 - 30 inchesPerfect for babies who have grown a little and need a bit more room but are still in a crib.
Large12 - 18 months24 - 30 lbs30 - 34 inchesDesigned for toddlers who are transitioning to a larger sleeping space.
X-Large18 - 24 months30 - 36 lbs34 - 38 inchesFor older toddlers who need more space to move but still benefit from the security of a sleep sack.

How to Choose the Right Baby Sleep Sack:

  1. Age and Weight:
    • The most common factors for selecting the right sleep sack are the baby's age and weight. These help in determining how long the baby has been in the current growth stage and whether they are still within the recommended weight for the size.
  2. Length:
    • Length is essential to ensure that the baby isn't restricted in their movement but also not too loose where they could slip inside or get tangled. The length in the chart provides a good guideline for this.
  3. Consider the Season:
    • Depending on the season, some sleep sacks come with different levels of warmth, measured by TOG (thermal overall grade). Choose a sleep sack that will keep your baby comfortable based on the temperature of the room where they sleep.
  4. Fit:
    • The fit of a sleep sack is essential for safety. The sack should not be too tight around the neck or chest to avoid restricting breathing. It should allow the baby to move their legs and arms freely but also prevent them from slipping down into the sack.
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