Baby & Kids Sleeping Bag Size Guide
Choosing the right size sleeping bag makes all the difference to your little one’s comfort and safety. At Slumbersac, we always recommend measuring your child’s height rather than relying on age, as every baby and child grows at their own pace. Our age ranges are there as a guide, but height gives the most accurate fit.
Important: It’s best not to size up. If a sleeping bag is too big, it won’t be as safe and your child could slip down inside. The safest fit is one that feels snug around the shoulders and neck while still giving plenty of room to wriggle and kick their legs.
Sleeping Bag with Feet Sizes
Our Sleeping Bags with Feet are available from newborn up to 10 years, giving little ones the comfort of a sleeping bag with the freedom to move. They’re designed so babies can wriggle and crawl safely, while older children can walk and play before bedtime. Always choose the size based on your child’s height, not age, to ensure the best fit. With practical features like foldable feet covers, little ones can keep toes cosy at night or free during the day.
Example: a toddler measuring 73cm would usually wear a 70cm sleeping bag with feet (approx. 12–18 months).
Baby Sleeping Bag Sizes
Our Baby Sleeping Bags are available from newborn and provide a safe, cosy alternative to loose blankets. To find the right size, always measure your baby’s height, not age, as little ones grow at different rates. A safe fit means the neck and arm openings sit snugly while leaving plenty of room for legs to move. Your baby’s feet should rest about three-quarters of the way down the sleeping bag, leaving the bottom quarter free for kicking and wriggling.
Example: a baby measuring 75cm would usually wear an 80cm baby sleeping bag (approx. 6–12 months).
Longer Lasting Size Fact: Did you know that our size 110cm can be shortened to 90cm with Velcro tabs, so the sleeping bag adjusts as your child grows and can be used for longer.
Adult Sleeping Bag Sizes
Our COZY by Slumbersac is an Adult Sleeping Bag with Feet, designed for comfort at home or away, giving the same warmth and practicality as our children’s range. To find the right fit, measure your height and chest circumference rather than clothing size. The bag should feel roomy enough to move around in, but still sit comfortably at the shoulders.
Example: someone 174cm tall with a 100cm chest would usually wear a Medium Adult Sleeping Bag.
Tips for Choosing the Right Size
✔ Always measure by height, not clothing size or age
✔ Do not size up – a bag that’s too large may be unsafe
✔ The neck and arm openings should fit snugly but comfortably
✔ Your child’s feet should never reach the very bottom of the bag
✔ Use our handy size guide on product pages for a quick guide
FAQs – Sleeping Bag Sizes
What if my child is between two sizes?
It's best to choose the smaller size. It’s safer and still allows for movement.
How do I measure my baby for a sleeping bag?
Lay your baby down and measure from the top of their head to the bottom of their heels. Use this height to select the correct size.
What if my child is very slim or very chunky for their height?
Always use height as your main guide. Our sleeping bags are designed with enough width to allow wriggling, but still fit safely at the neck and shoulders.
Do sleeping bags with feet fit the same as baby sleeping bags?
Yes, both are based on height, not age. The difference is that sleeping bags with feet give extra freedom once babies start crawling or walking.
Can newborns use baby sleeping bags or sleeping bags with feet?
Yes – our sleeping bags with feet are available from birth. For newborns, the feet covers can be kept closed to keep them snug.
Do adult sleeping bags with feet come in different TOGs?
Yes, our COZY by Slumbersac are available in a range of TOG ratings, so you can choose the right warmth level for the season.
What if I pick the wrong size?
Don’t worry – you can exchange or return your sleeping bag. Please see our returns policy for details.
