Size 5 diaper: up to what age or weight?

In collaboration with Rokiyah Hosen

Relecture professionnelle

Your baby is starting to walk and is showing signs of wanting to do everything on his own. And for some time now, you've been feeling that your baby's diapers are too small.

You're wondering whether it's time to upgrade to the next size up: size 5. How much does your baby need to weigh to go up to this size? Should you use diapers or pants? We answer all your questions in this article.

Everything you need to know about size 5 diapers

The size 5 baby diaper is suitable for babies weighing between 11 and 25kg. It is estimated that the average baby can wear it from 18 months onwards. Of course, it all depends on your child's morphology. Some babies will switch to a size 5 diaper as soon as they blow out their first candle.

Like size 4 diapers, size 5 diapers are worn by your baby for several months.

When should I start using size 5 diapers?

To know when to choose the next size up, there are several things to consider:

  • You notice recurrent leaks;
  • You can no longer fit two fingers between the diaper and your baby's tummy;
  • You notice red marks on your baby's skin when you change his diaper;
  • You have trouble closingyour baby's diaper;
  • Your baby makes you feel that his diaper is too small, for example by pulling on it.

All these indicators should let you know that your baby's diaper size and that it's time for a new one.

How many size 5 diapers should I buy for my baby?

As with size 4, size 5 is a diaper that will be worn for a long time. Don't be afraid to stock up on several packs of diapers in this case. They will be used.

Below is a summary of the number of packs of diapers to buy according to baby's weight and age:


Number of size 4 packs

Number of packs in size 5

Number of packs in size 6

from 10.5 to 12.5 kg



from 12.6 to 13 kg


from 13.1 to 13.5 kg



+ over 13.5kg


If you're wondering whether you'd be better off with panty diapers rather than size 5 diapers, they have both advantages and disadvantages: they're easier to put on and take off. Panty diapers are particularly suitable for potty training.

It's estimated that potty training begins around the age of 2, depending on your child's development. So, if your baby is still under the age of 2, it's best to stick with diapers.

Once your child has blown out his second candle, it will be easier to teach him to become potty-trained. At that point, it's a good idea to switch to diapers or training pants.

At night, however, it's best to stick with regular diapers.

How to choose the best size 5 baby diaper?

As well as choosing the right size diaper, it's important to choose a good-quality diaper that's soft and comfortable for your baby, and above all, healthy.

Indeed, your baby's skin is very fragile and is in direct contact with his skin.

To ensure that a diaper is healthy and made from skin-friendly materials, there are several criteria to consider:

  • First of all, you can consult the chemical analysis results of diaper brands. Make sure they contain no toxic products. If you can't access the analyses, that's a bad sign;
  • Beware of claims such as "dermatologically tested", "hypoallergenic" or "FSC certified". These terms are mandatory, but in no way guarantee that the diaper is non-toxic;
  • Then check the diaper's composition in detail to make sure it contains no substances such as perfume, lotions, allergies or irritations. Also check that the diaper's elastics are latex-free;
  • You can also check the bleaching method used. Today, most diapers are bleached using the ECF (Elementary Chlorine Free) method, which uses chlorine derivatives, and only 5% of diapers on the market use the TCF (Totally Chlorine Free) method, which uses neither chlorine nor chlorine derivatives;
  • It's also advisable to choose ecological or organic disposable diapers rather than conventional ones. Ecological and organic diaper brands are generally more careful in their choice of raw materials and manufacturing processes. The more natural materials a diaper contains, the better.

You might think that ecological diapers absorb less. But this is totally false: organic and/or ecological diapers absorb as well as, or even better than, disposable diapers.

Ecological diapers actually reduce the concentration of synthetic material in the absorbent part, replacing it with natural cellulose.

Baby's growing: when to change to a size 6 diaper?

Your baby's still growing, and you're wondering whether it's time to switch to a size 6 diapers ?

As with the transition from size 4 to 5, if you notice regular leaks, red marks on your baby's skin, and if you can no longer fit two fingers between the diaper's elastic and your baby's tummy, it's time to move up to the next size.

To potty train your baby, we recommend the use of training pants. They work on the same principle as diapers, but they allow you to reduce your waste considerably.