You are in the CalmFamily

Sling and carrier weight limits: what do they actually mean?

Dad carrying 4 year old in sling
Share this article:
Share on facebook
Share on twitter
Share on linkedin
Share on pinterest
Share on email

Sling and carrier weight limits: what do they actually mean?

Dad carrying 4 year old in sling
Share this article:
Share on facebook
Share on twitter
Share on linkedin
Share on pinterest
Share on email
This resource is categorised as:
This resource is listed in the following topics

  Most slings and carriers have several weight limits on the box.

  • Minimum weight limit to use the carrier
  • Maximum weight limit to use the carrier
  • Minimum weight limit to stop using the insert in the carrier
  • Minimum weight for using different positions such as facing away, back or hip carrying

What do these weight limits mean?

Weight limits on slings and carriers are either set by the manufacturer, or are the result of testing in a laboratory.  

Minimum weight limits are usually set by the manufacturer, based on two things; firstly, the average weight of a baby whose size would allow them to safely use the carrier in a specific position; secondly, low birth weight babies may have additional needs and complications and manufacturers cannot be sure their carrier can meet those needs. It may be possible to safely carry them in that sling. However, it is advisable to get individualised specialist help from a consultant who can check it meets their needs first. Minimum weight limits, therefore vary between different slings and carriers. They vary between manufacturers, and country of origin where different laws may govern the selling of baby products. They also vary for different positions in the same carriers.

Maximum weight limits for carriers are generally set by doing laboratory testing.  

How carriers are weight tested

A common way a carrier is weight tested is by bouncing a cylinder of material of a specific weight on the carrier a set number of times. If the carrier remains undamaged it passes testing at that weight. If the carrier is damaged it can be re-tested at a lower weight; carriers that pass can be tested at higher weights. Laboratories offer specific weights for testing, and tests cost manufacturers considerable money.

A carrier may have a maximum weight because they only tested to a weight they were confident most people would use a carrier to or because the laboratory didn’t offer tests to higher weights . Maximum weight limits are the weight that a carrier was able to carry and pass these tests.  Testing doesn’t remotely resemble carrying a baby. A carrier can pass a test that says it can withstand weights of 45lb, but not be suitable for you to carry your 45lb child. The carrier may not break, but it may not offer enough support; it may not be large enough; it may not be comfortable for you or your child. A child sits differently in the carrier than a baby.  Your child can be within the carrier weight limit, and yet it not be safe.

All babies are different

Weight or size

Babies are all different weights at different ages and stages and all babies develop at different speeds. So two 7lb babies might be very different sizes and ages from one another and so might two 15lb babies. How large a baby is – the length of their torso and legs – might not be easy to tell from their weight.   If you only look at weight then it is very easy to assume a carrier will be fine but is actually not suitable for your baby.

Infant inserts

Let’s consider carriers with infant inserts. We suggest that you use the infant insert until your baby is 4-6 months old. These weight limits on these carriers often say to use the insert until your baby is 13lb. This could be at a few weeks old (my second child was 13lb at just over 2 weeks). A 3 week old baby is not large enough or developmentally ready to use a non adjustable carrier without an insert. The insert provides more support to hold a baby upright, and takes up some of the space that a young baby does not fill. Most 4-6 month old babies are large enough to fill the carrier; this makes it more supportive for them. They are also better able to support their own weight.

sling school stretchy wrap newborn tester two way purple pink short long weight limits comfy safety safe

Over the carrier weight limit

At the other end of the spectrum if you have a child who is 25kg and as such over the higher weight limit on most carriers, the carrier doesn’t necessarily become unsafe. As the testing is costly most manufacturers will simply not have tested to a higher limit. That is very different to them having tested to weights over 25kg and failed. So it is likely that the carrier could still comfortably and safely support your child, if it is large enough.

But the carrier still has these guidelines?

The catch is that if you do use a carrier with a child whose wight falls outside the manufacturer’s set minimum or maximum weight limits then you are acting outside their guidance. If an accident occurred or the carrier failed the manufacturer will not accept liability. With very small babies we highly recommend getting advice from a trained sling consultant. If there are unusual circumstances, or when carrying a very heavy older child, we suggest similar.  

When carrying children over the carrier weight limit we suggest you check your sling regularly for wear and tear, especially on areas of strain, such as where straps attach, and the you regularly check webbing and buckles. It is extremely unlikely that a carrier will suddenly and catastrophically fail, and much more likely that it will gradually deteriorate under strain. We suggest doing this even when your child is within the weight limits, because accidents happen. Carriers get damaged.

Boba Stretchy Wrap

How can I check safety and fit?

There is plenty of professional advice available! From us here at It’s A Sling Thing to your local sling library or consultant, to large groups on Facebook there are ways to get some input on the fit of a carrier.  We have a really helpful article called Does My Sling Fit OK? that can help you check for yourself.

stretchy wrap sling supporting baby for breathing and safety good fit


With all carrying remember that there are two key factors for safety

  1. Your baby can breathe and their airway cannot become compromised; they are supported so that they can breathe; you can see or otherwise monitor this
  2. Your baby is secure and cannot fall out of the carrier; you don’t need to use your hands to support them whilst in the carrier; and the carrier is undamaged

These can be true even outside of the given carrier weight limits, or false even when your child is within the given weight limits. Always make sure that the carrier you are using can support your child safely.  


Beyond safety, look for comfort first for your child and then for you

Dad carrying 4 year old in sling
  1. Does the sling or carrier offer support from knee to knee (and no further) for a child under 1, or to mid thigh for an older child? Can they bend their knees freely?
  2. Are your child’s knees up above or level with their bottom?
  3. Does the carrier support your child’s spine smoothly, free from wrinkles and pressure points?
  4. Are your child’s hands up and accessible to them?
  5. Does the carrier support to the right height for your child’s age – to the back of the neck on a newborn, across the shoulders from 4+ months and up to the armpits for a toddler

All these points could be true in a carrier where your child is outside of the weight limits, or not true when your child is inside the weight limits for your sling.   Always look at your child and your carrier and check for safety first and then check the fit of the carrier for your child. With all parenting choices you can choose to asses risk for your own child. Weight limits can be useful information, but check that the carrier is safe and fitted correctly as well.   For more reading about safety head over to our Sling Safety page. To read more about common transition points when you may want to change your sling why not read Help! Do I Need To Change My Sling?   If you’d like some support choosing a sling why not book a consultation via phone or Zoom? 15 minutes on the phone is FREE!

Recommend0 recommendationsPublished in Carrying, Carrying basics, Carrying safely, Sling care, Sling choice & fit
Resources by category
Resources by topic
Resources by type

Post comments


Your email address will not be published. Required fields are marked *

Online groups

Ask in a forum

Find a consultant