Diaper size 1: until what age or weight of baby?

You are getting ready for the birth of your baby and among the many baby equipment to plan for his arrival is the question of diapers! Indeed, for his first months, even years of his life, you will spend a good part of your time in the changes. So, which size to choose for baby ? What are the size 1 diapers?


Everything you need to know about size 1 diapers

Size 1 di apers generally have the same characteristics as the bigger sizes ! Same materials, absorption etc... This type of absorbent product for urine and stools of the infant is generally composed of a skin contact layer, anti-leak barriers, an absorbent material and an anti-leak material.

Size 1 is simply the right size for the smallest newborns, from infants up to 2 to 3 months old. More than an age range, it is recommended to choose the size of the diaper according to the baby's weight, because not everyone has the same morphology and growth at the same age, and a baby who is lighter or bigger than his diaper size could leak! Size 1 diapers are therefore generally suitable for babies weighing from 2 kg to 5 kg.

When should I start using size 1 diapers ?

From birth, except for very premature babies who will wear a size 0 diaper! Size 1 diapers are perfectly adapted from 2 kg, knowing that the average weight at birth varies from 2,5 kg to 4 kg : this makes size 1 the perfect candidate to equip your baby's little buttocks during his first weeks. This size 1 will be ideal in most cases : you can foresee a few packs of diapers for your baby's future room.

How many size 1 diapers should I buy for my baby ?

You should count on average 8 diapers per day during the first 3 months of your baby's life. So in theory you will need about 700 diapers!

If the medical profession predicts a big baby at birth, you can simply buy size 1 diapers for the first 2-3 weeks of life, i.e. about 150 diapers, and then go directly to size 2. It is important to know that even if you are told that your baby weighs 4kg or more at birth, and that he could in theory go directly to size 2 (3 to 6kg generally), it is normal that the baby loses on average 10% of his birth weight during the first days, and that it takes some time to get back to his normal weight. At the maternity hospital, diapers are sometimes provided, sometimes it is up to you to bring them back: ask the question to find out. For an average stay of 3-4 days, a single package to put in your maternity suitcase will be enough for his first days of life.

When you become a mom or dad, you tend to want to plan everything, but don't anticipate your baby's growth too quickly: there is no point in equipping yourself for more than a month for his toilet, he could exceed his weight curve more quickly than expected, and you could end up with ill-fitting diapers! Keep in mind that one baby can grow quickly and in spurts, while others may struggle to keep up with their weight curve in the first few weeks.

You can store the rest of the toiletries and hygiene products, such as wipes, liniment, cleansing water, etc., for a longer period of time if you want to buy in batches. If you are afraid to have time to think about restocking your diapers during your postpartum period, don't hesitate to subscribe to a subscription system, which offers you for the most part an evolution of the sizes shipped over the months, to follow the growth of your offspring.

You will find below a summary of the quantities of diapers to plan for the first 100 days of your child, based on a package of about 30 diapers. It is purely indicative because each child has his own growth rhythm at this age.


Expected birth weight

1st month (Nbr of packs of diapers needed)

2nd month (Nbr of packs of diapers needed)

3rd month (Nbr of diaper packs needed)

from 2,5 to 3 kg

8 packs Size 1

8 packs Size 1

4 packs size 1
4 packs size 2

from 3,1 to 3,3 kg

8 packages size 1

6 packages size 1
2 packages size 2

8 packages size 2

from 3.4 to 3.6 kg

6 packs size 1
2 packs size 2

4 packs size 1
4 packs size 2

8 packages size 2

from 3.7 to 3.9 kg

4 packs size 1
4 packs size 2

8 packs size 2

6 packs size 2
8 packs size 3

+ over 4 kg

1 pack size 1
7 packs size 2

8 packs size 2

8 packs size 3


How to choose the best size 1 diaper?

The best diaper for baby is the one he tolerates the best! Some infants are particularly sensitive to irritation and erythema on the seatThis is why you should not hesitate to change brands if you notice redness despite a regular change.

In general, it is wise to say that a clean, chemical-free composition and ecological or cotton materials in contact with the skin are good indicators that a diaper is safe for baby's skin! Eco-friendly diapers using natural materials (cotton, cellulose) will be better for your baby. Don't always rely on marketing speeches, which sometimes distort reality: look for external and independent certifications to validate the safety of the product. Don't forget that your baby wears a diaper 24 hours a day for the first few years of his life, in constant contact with his sensitive skin, in a context of humidity and acidity.

Concerning the debate between disposable and cloth diapers, each one has its advantages and disadvantages. In terms of cleanliness andirritation, disposable diapers, although more polluting, are healthier for your child.

Look regularly at the publications of the ANSES (Agence Nationale de Sécurité Sanitaire) and the DGCCRF (Direction Générale de la Concurrence, de la Consommation et de la Répression des Fraudes) on the safety of the materials and manufacturing of diaper brands. The analysis reportsmust also be available at the brand you have selected!

Finally, a good absorption, without leakage, is a guarantee of serenity for you and your child!

When to change baby's diaper for size 2?

To know when it's time to change to the next size, here are a few clues to help you:

  • You are having more and more trouble getting the tapes to fit over the waist, or they are unraveling quickly;
  • Your baby seems to be tight and his skin is marked by the elastic when you change him;
  • You notice more leaks and spills (hello stains on onesies!);
  • It is no longer possible to put two fingers between baby's belly and his diaper.

Then, it's because baby has grown and it's time to buy him diapers size 2 !

Les informations issues des articles présents sur le site www-elia-lingerie.com sont des informations générales. Bien qu’elles aient été relues par des professionnels de santé, ces informations ne sont pas exemptes d’erreurs, ne constituent pas des conseils de santé ou des consultations et n’ont pas vocation à fournir un diagnostic ou proposer un traitement. Ces informations ne peuvent, en aucun cas, se substituer à un avis médical et ne peuvent pas remplacer une consultation auprès d’un professionnel de santé. Pour toute question, nous vous invitons à consulter votre médecin.