Pregnancy when I'm due a calculator

SSW calculator: calculate the due date and SSW

Content checked by physician Dr. Dominik Panosch

During pregnancy you will often come across the term SSW (pregnancy week). It shows the current state of pregnancy in weeks. It is usually shown in weeks and numbers, such as 13W + 3 (13 weeks + 3 days). In this case you would be in the 14th week of pregnancy.

So that you too can calculate your current SSW precisely, we have developed a SSW calculator that shows your current status 3 different methods can calculate:

  • 1) After the first day of your last period
  • 2) After the time of fertilization
  • 3) According to the expected due date

The SSW calculator (pregnancy calculator)

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We accompany you week after week through the pregnancy, because with us you will find exciting reports on every single week of pregnancy with pictures and videos. So you can find out every week what is going on in your body and how your little baby is developing. You can use the pregnancy calculator above to determine which week of pregnancy you are currently in.

All weeks of pregnancy at a glance

Here you can find an overview of all 40 weeks of pregnancy. Use our SSW calculator to find out what week you are currently in.

1st week of pregnancy: The start of a new cycle
At the beginning of every pregnancy there is a new cycle. A cycle usually lasts between 24 and 36 days, but it can also be longer or shorter. It begins with the menstrual period and ends before the day of the next menstrual period. The 1st week of pregnancy is already counted among the 40 weeks of pregnancy.

2nd week of pregnancy: the beginning of fertility
The 2nd week of pregnancy marks the beginning of fertility in your cycle. Your ovaries are working at full speed and one or two follicles grow in which the egg is located.

3rd week of pregnancy: pregnancy begins
In the 3rd week of pregnancy pregnancy really begins when a sperm has made it to the egg cell and fertilized it. For the fertilized egg it is now a matter of finding a cozy place in the uterus and diligently sharing so that a baby can emerge from it.

4th week of pregnancy: Small as a poppy seed and a lot of luck
Your baby is barely the size of a poppy seed this week and it can make you feel so happy just by holding the positive pregnancy test in your hand. This moment, which will change your life quite a bit, can possibly already occur at the end of the 4th week of pregnancy.

5th week of pregnancy: The little heart begins to beat
The information about the pregnancy is still very fresh and everything feels new to you. Even if you haven't noticed much of the embryo yet, a lot is already happening in your body. When you have reached the end of the 5th week of pregnancy, the little heart will already start beating and can sometimes even be seen on the ultrasound.

6th week of pregnancy: The baby doubles in size
The baby is now growing in your tummy for around four weeks and even if it is still tiny, it is already doing great things. In the 6th week of pregnancy, the embryo doubles its size and already gains weight.

7th week of pregnancy: The baby's first movements
Of course, it will be a few more months before you can feel the first gentle nudges from your baby yourself. Before that, however, the embryo is already practicing very diligently and thus it begins around the 7th week of pregnancy. He slowly makes the first movements, which are still uncontrolled at the beginning and primarily serve to build up the muscles.

8th week of pregnancy: An important time for the development of the senses
The human being is shaped by his senses. Hearing, tasting, seeing, feeling and smelling are essential for personal development. An important foundation stone is laid for your baby as early as the 8th week of pregnancy. Both the eyes and the inner ear are further developed.

9th week of pregnancy: The construction of the important organs is finished
At the 9th week of pregnancy you enter the third month of pregnancy and the first trimester is nearing the end. All important organs are now in your baby. This leaves the embryonic phase behind. From a medical point of view, it is now referred to as a fetus until it is born.

10th week of pregnancy: The little person is almost perfect
With just around 3 cm in the tummy, your baby is still really small, but it almost looks like a perfect person. In the meantime, the toes and fingers have developed even more, the face is clearly recognizable and the head has straightened up further.

11th week of pregnancy: focus on the development of the sense organs
Even if your baby is still relatively small in the 11th week of pregnancy, it is already very well developed. The critical phase of organ development is almost behind you. The sense organs are now in the foreground. The functions of the nose and mouth are further developed and the taste buds slowly develop.

12th week of pregnancy: From hiccups and tooth buds
The first critical trimester is drawing to a close and the sperm and egg have now become small people. The organs are laid out so that fingers and toes can be seen. Now it's time to fine-tune. In this week of pregnancy, the first tooth buds are formed, from which the small milk teeth later emerge.

13th week of pregnancy: focus on growth and maturation
In the last weeks of pregnancy it was particularly important that all the foundations for the baby's development could be laid. In addition to the system and growth of the organs, small things such as the fingernails and toenails have already formed. Now the time begins when your baby is mainly busy growing.

14th week of pregnancy: The lanugo hair is growing
Your baby's small body is now covered in soft lanugo hair. It serves as protection for the skin and falls out before birth. In some cases, babies still have thick hair on their skin.

15th week of pregnancy: Mom's voice hits the stomach
The 15th week of pregnancy is a real milestone for the baby in your belly, because the hearing is now so well developed that it can finally hear the voice of mom. In addition to your voice, it is above all the heartbeat that reaches your baby and has a very calming effect on the little person.

16th week of pregnancy: The hormone production really gets going
Your baby's thyroid is really busy from the 16th week of pregnancy, because now more and more hormones are produced that are important for development. In doing so, however, she needs support. For this reason, it is particularly important that you get enough iodine from your diet.

17th week of pregnancy: activity for training the muscles
Movement is your baby's current hobby. It moves through the uterus with a lot of joy and begins to control its own movements more and more. Up until now it was often more of a coincidence in which direction the movements went, now your baby learns to move the arms or legs in a certain direction.

18th week of pregnancy: Lots of sleep for growth
Some women feel like the baby is always active in the womb at a similar time. In fact, in the 18th week of pregnancy, no rhythm has yet developed that is noticeable. The baby sleeps a lot in the stomach. It takes around 20 hours to sleep in peace and to recharge its batteries in order to continue to grow.

19th week of pregnancy: The sense of touch is already working well
For your baby, the sense of touch is already a very important property in the stomach, which is now quite well developed in the 19th week of pregnancy. It now comes to the uterus more and more often with its hands or feet and when this happens, your baby pulls his hands or feet back again. So it slowly notices the limitations in the stomach.

20th week of pregnancy: Enjoy with all your senses
The 20th week of pregnancy is again an important milestone for your baby, because now everything revolves around the further training of the senses. The sense of smell and taste, the sense of touch, hearing and eyesight develop better and better. In the meantime, the eyes even react when bright light falls on the stomach, even if they are still closed.

21st week of pregnancy: The rhythm of the sleeping and waking phases
The baby sleeps in the stomach for around 20 hours and this sleep is urgently needed, because all the developments are a real high performance for the small body. However, it has now reached the point where you may notice certain waking phases in your stomach. In fact, at 21 weeks of gestation, babies begin to slowly develop a rhythm.

22nd week of pregnancy: The hiccups can be felt
Your baby has had the hiccups for a few weeks, but so far you haven't noticed. That changes slowly from the 22nd week of pregnancy onwards. The baby has now reached a size at which, depending on its position, it can also hit the abdominal wall when it is shaken by the hiccups.

23rd week of pregnancy: The distinction between the noises
The development of your baby's inner ear bone is very exciting in the 23rd week of pregnancy. This was still not hardened. This allowed your baby to hear the sounds, but not yet properly differentiate them. That is changing now, because the bone hardens more and more.

24th week of pregnancy: sweet, sour or salty - taste for the baby
Your baby's taste buds are already really well developed and in the 24th week of pregnancy it begins to notice more and more different taste differences. This is how your baby absorbs amniotic fluid and tastes good, whether it is salty, sour or rather sweet.

25th week of pregnancy: The sense of balance is on the advance
Balancing one's own posture is a very big challenge for toddlers that has to be learned little by little. The basis for this is the sense of balance and this is now developed in the 25th week of pregnancy. Your baby is now better and better able to influence its own posture.

26th week of pregnancy: The grasping reflex is trained further
The umbilical cord is your baby's favorite toy. There is a lot of joy in catching her, moving her hands and toes, reaching for her and playing with her. But this is not only very good entertainment for the little person in your stomach, but also an ideal way to train the gripping reflex.

27th week of pregnancy: The cerebral furrows are further developed
An important focus in development in the 27th week of pregnancy is on the brain. Up until this week the surface was kept relatively smooth. That changes more every day because the furrows in the brain develop. This also has an impact on your baby, because he will probably have his first dreams now.

28th week of pregnancy: The fine work on the brain continues
As early as the 27th week of pregnancy, furrows slowly formed in the baby's brain. Even in the 28th week of pregnancy, the brain continues to be provided with furrows and the more they increase, the more the brain activity of your baby increases. In this way, the sensory perceptions are becoming more and more differentiated.

29th week of pregnancy: Now it's the baby fat
In the 29th week of pregnancy, organ development has almost reached its end point and in the next few weeks the main focus will be on your baby gaining more and more weight and size. With a height of just under 38 cm and a weight of around 1,200 g, there is still a lot to do before birth, because the average baby then has a size of around 50 cm and a weight of around 3,480 g.

30th week of pregnancy: The baby and the pain stimuli
The 30th week of pregnancy is an important milestone, as researchers have found. The baby is now able to recognize pain stimuli and feel pain in the process. This realization is not that old at all. After all, doctors were of the opinion that neither fetuses nor infants are able to feel pain.

31st week of pregnancy: An important time for the lungs
The 31st week of pregnancy is a particularly important time when it comes to the baby's breathing. The lungs are now mature enough to be able to inflate. The production of Surfacant continues to increase and ensures that the lungs cannot stick together.

32nd week of pregnancy: The search for the right position
Up until now, the baby still had plenty of room in your tummy to do one or the other turn. However, it is slowly getting tighter and so many children decide as early as the 32nd week of gestation to take the final birth position. You will probably feel this too.

33rd week of pregnancy: The rapid growth of the brain
The brain is already well developed in the 33rd week of pregnancy, but there is still a lot going on here in the next few weeks. For example, the circumference of the head increases by over 1 cm in the 33rd week of pregnancy and this is due to the fact that the brain volume increases significantly.

34th week of pregnancy: The lungs are finally ripe
In the case of premature labor before the 34th week of pregnancy, the lungs are the main cause for concern. Therefore, there would still be a lung maturity to support this development. By the 34th week of pregnancy, lung maturity is finally complete and the baby would normally be able to breathe on its own if it were born too early.

35th week of pregnancy: The baby and its dreams
Have you ever thought that your baby isn't dreaming yet? Researchers have found that this does happen after all. It is assumed that your baby is already dreaming very intensely in the 35th week of pregnancy. The fact that even unborn babies already have a REM phase is particularly exciting.

36th week of pregnancy: The search for the starting position
Maybe you worked towards 36 weeks in the hope that your baby would still turn. This wish is understandable, especially if it has been in the breech position up to now. Doctors and midwives give the babies until the 36th week of gestation so that they turn on their own. If this has not happened so far, an attempt will now be made to lure the baby.

37th week of pregnancy: The brown adipose tissue increases
Your baby has already gained significant weight in the last few weeks and has created more and more fat deposits. By the 37th week of pregnancy, the fat reserves have already increased significantly. This is especially important for your baby too.

38th week of pregnancy: Fine work on the lungs
In the 38th week of pregnancy your baby will be ready for birth and it may well be that you will be able to hold your offspring in your arms this week. However, it does not harm the baby if it stays in the tummy for a few more days, because now it's about the final fine-tuning on the lungs. This begins to produce cortisone.

39th week of pregnancy: The storage of fat reserves
The 39th week of pregnancy has been reached and we can start every day. The 10th month of pregnancy is drawing to a close and your baby is ready for birth. If this takes a little longer to come, it will continue to use the time effectively because it builds up even more fat reserves.

40th week of pregnancy: The baby is ready to go
When you have reached the 40th week of pregnancy, you are officially in the last week of pregnancy and you are now almost 10 months pregnant. In these 10 months a poppy seed has become a strong baby that can now be on its way every day. Your baby is basically ready to go.

You don't know what week of pregnancy you are in? Then use our pregnancy calculator / SSW calculator (at the top of this page).

FAQ - Frequently Asked Questions

How can I calculate my current SSW?

You can use our SSW calculator for the calculation. There are 3 ways in which you can calculate your current week of pregnancy: after the first day of your last period, after the time of fertilization or after the expected due date. Choose one of the three options and you will find out your current pregnancy week to the day.

To the SSW calculator ...

What does pregnancy week mean anyway?

During pregnancy you will often come across the term pregnancy week (SSW). It shows the current state of pregnancy in weeks. It is usually shown in weeks and numbers, such as 13W + 3 (13 weeks + 3 days). In this case you would be in the 14th week of pregnancy.

To the SSW calculator ...

How many weeks of pregnancy are there?

There are a total of 40 weeks of pregnancy and the pregnancy lasts about 280 days. The calculation starts from the first day of the last menstruation.

To the SSW calculator ...

How many babies will be born on the expected delivery date?

In a survey of 2,000 mothers, YouGov found that only about 9% of babies are born on time, i.e. on the calculated delivery date. 49% were born before the calculated date and 42% after this date. In most of the births, however, the deviation from the expected delivery date was only a maximum of 10 days. Premature births (before the completed 37th week of pregnancy) affect around 12% of all babies, late births (after the completed 42nd week of pregnancy), on the other hand, are significantly less common.

By the way: On the day before and after the calculated delivery date, around 4% of the babies were born. The calculated delivery date actually has the best hit rate at 9%.

To the SSW calculator ...

Why is the calculated due date important at all?

During pregnancy you need a fixed point to be able to determine which week of pregnancy you are in, how the baby is developing and to be able to start the examinations at the gynecologist afterwards. This date is also extremely important for maternity protection, as it determines the start of the maternity protection period.

To the SSW calculator ...


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Nadine Beermann is trained Midwife and postnatal coach with almost 20 years of experience. In addition to her own midwifery practice near Fulda, she also offers online birth preparation and postnatal training courses.