2. KNOWLEDGE, Development
Online calculator: Height and weight of babies by age (0-3 months)
With this online calculator 🧮 you can check whether your baby’s growth 👶 is progressing normally: Find out your baby’s ideal height and weight in the first three months of life, and when there is a risk of overweight/underweight or growth disorders.
Also applicable for premature babies & late births!
Online-Rechner: Größe & Gewicht von Babys, 0-3 Monate
Operating instructions Online calculator
This online calculator is used to determine the height and weight of healthy babies in the first three months of life based on data from the World Health Organization (WHO).
- SSW SSW = “week of pregnancy”.
Indicate here in which week of pregnancy(SSW) the baby was born, i.e. whether it is a premature birth or a late birth.
A normal pregnancy lasts approx. 40 weeks (SSW: 40). - Age in weeks The current age of the baby in weeks.
- Ø Ø = average.
Average weight and average height of other babies of the same sex and age as your baby. - Min./Max. confidence interval: Min = minimum; Max.
= maximum. 95% of babies born worldwide have growth values (weight and height) that lie between these two extreme values.
Only 5% of babies fall outside this interval.
If your baby is one of these 5%, this could be an indication of a growth disorder.
A visit to the pediatrician would be advisable.
Gewichts- und Größentabelle, Babys 0-3 Monate
Durchschnitts-Gewicht und Größe für gesunde Babys (Mädchen und Jungen) in den ersten drei Lebensmonaten.
Vereinfachte Darstellung basierend auf den Daten der Weltgesundheitsorganisation (WHO).
👉 Hinweis zur Verwendung bei Frühchen (z.B. Zwillinge) & Spätgeburten weiter unten
Gewichtszunahme und Größenwachstum bei Babys 0-3 Monate – grafische Darstellung
Durchschnitts-Gewicht und Größe für gesunde Babys (Mädchen und Jungen) in den ersten drei Lebensmonaten mit 95%-Konfidenzintervall (2 Standardabweichung (2σ-Intervall)). Man beachte die Offsets auf der Y-Achse!
Diese ausführlicheren Darstellungen basieren ebenfalls auf den Daten der Weltgesundheitsorganisation (WHO) – Link unten im Literaturverzeichnis.
Interpretation: Gut 95% der weltweit geboren Kinder weisen im Verlauf der ersten 13 Lebensmonate Messwerte hinsichtlich Körperlänge und Gewicht auf, die zwischen den beiden äußeren Kurven liegen. Gehört dein Baby nicht dazu, könnte dies ein Indiz auf Untergewicht oder Übergewicht bzw. auf Wachstumsstörungen sein.
👉 Hinweis zur Verwendung bei Frühchen (z.B. Zwillinge) & Spätgeburten weiter unten
Gewichtszunahme in den ersten 13 Lebenswochen bei neugeborenen Mädchen (♀) & Jungen (♂) – grafische Darstellung
Größenwachstum in den ersten 13 Lebenswochen bei neugeborenen Mädchen (♀) & Jungen (♂) – grafische Darstellung
Important note on use for premature babies and late-term babies:
For premature babies, when looking up the corresponding values in the tables and graphs, you must reduce the age by the time delta of the premature birth.
Determining the time delta A normal gestation period of 40 is used to determine the time delta.
For a newborn that is born after 35 weeks of pregnancy, for example, the time delta is -5 weeks.
To read the data from the tables and graphs correctly, you must therefore subtract 5 weeks from the actual age of the baby.
In this case, the table only makes sense from an age of 5 weeks. Concrete example Twins are often born earlier.
For example, let’s look at a pair of twins (girl and boy) who were delivered by caesarean section at the beginning of the 36th week of pregnancy (week 36).
The two babies were therefore born almost 4 weeks earlier than is normally the case with single babies.
At the age of 8 weeks, their weight and height should therefore have the same measurements as a 4-week-old baby born in the 40th week of pregnancy, i.e:
- Girl: 4.1 kg; 53.4 cm.
- Boy: 4.4 kg; 54.4 cm.
Online calculator When using the online calculator, there is no need to fiddle with the time delta.
This is already taken into account by entering the number of weeks’ gestation (SSW) after which the baby was born.
Why is baby weight gain and growth so important?
Keeping regular records of your baby’s weight gain and growth can provide helpful information about your baby’s healthy development.
At the very least, they are good for your personal peace of mind.
If your baby’s weight is not changing according to the norm, this could be an indication of an illness (failure to thrive).
This could be the case, for example, if your baby is not eating properly or is not absorbing or using the nutrients from food properly.
It could be due to a feeding problem, a gastrointestinal problem or another illness.
If your baby has health problems, including unexpected weight loss or jaundice, more frequent visits to the pediatrician may be in order during the first few weeks of life.
What is the normal weight loss for newborns in the first few days after birth?
Most healthy babies lose between 5 and 10 percent of their birth weight in the first few days after birth.
This early weight loss occurs because babies are born with extra fluid that is excreted after birth.
This weight loss is normal and is not a problem unless your baby loses more than 10 percent of its birth weight.
What is the normal weight gain of a newborn baby in the first few weeks after birth?
Babies usually start to gain weight again after five to seven days after birth, and most should be back to, or even above, their birth weight by around 2 weeks of age.
Although most babies follow this trend, about 10 percent of healthy newborns regain their birth weight more slowly over several weeks.
Many factors play a role in a baby’s weight gain in the first few weeks of life, including how quickly your body is able to produce breast milk and how much your baby wants to eat.
Many mothers notice that babies between 7 and 10 days old want to eat more often or for longer.
This urge in the baby to be constantly breastfed is called cluster feeding.
This is nothing abnormal, and these continuous breastfeeding phases will eventually subside.
How do I know if my newborn is gaining enough weight?
Even if you don’t have a suitable scale at home to weigh a baby, counting your baby’s dirty diapers can help you determine if your baby is doing well: Wet diapers: While your newborn will only wet a few diapers a day for the first five days, this number can increase to at least four and up to eight wet diapers a day in the days and weeks that follow.
Stool diapers: In the first few days after birth, some babies only defecate once a day.
In the days that follow, this rate increases to at least two stools per day.
After the first week and up to the end of the first month, this rate increases to possibly 10 or more stools per day.
What can I do if my baby loses too much weight or doesn’t gain enough weight after birth?
If you notice that your baby is not drinking well or wetting a lot of diapers, it is always a good idea to visit the (pediatric) doctor.
Your baby will probably be weighed at regular intervals and you will be given advice on how to encourage your baby to eat more.
On our own behalf
ATTENTION!
This guide is not intended to replace a visit to the specialist!
It is also not intended to encourage you to give your child more or less to eat, change your baby’s food or change your behavior in any other way.
It should go without saying that free and freely accessible information from the internet such as this blog post cannot/should not replace specialist advice or a visit to the doctor.
This article is merely an easier-to-understand preparation and presentation of the already freely accessible information from the World Health Organization (WHO) using tools such as a more user-friendly online calculator, simplified table views and diagrams and a short advice section that has been researched and written by medical laypersons to the best of their knowledge and belief.
Yes, we also used this online calculator and guide to check the growth behavior of our own children – we created both at around the same time as they were born.
They were mainly for our own peace of mind and were never a reason to skip an appointment with the pediatrician or disregard the doctor’s advice.