How to calculate the exact gestational age. Accurate weekly pregnancy calculator

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The pregnancy calendar is a kind of list of all important points pregnancy. You can also use it to calculate the due date. In order to calculate when a long-awaited event will happen, you just need to:

  1. Remember the date of the last menstruation, for example: December 17, 2015.
  2. Then the most likely date of conception: January 1, 2016.
  3. Estimated date of birth of the child: September 22, 2016.

You can determine the expected date of birth yourself using a simple circuit calculation. To do this, remember the date of the first day of the last menstruation and add 280 days to this number.

Pregnancy calculator online

Especially for you, dear future mothers, the site has developed an online pregnancy calendar. With it, you can easily find out the date of the expected birth, the age of the baby in the tummy, how many days are left until a significant event, and also find out who your baby will be according to the zodiac sign.

First trimester of pregnancy

1st week. Now it is still difficult to talk about pregnancy as such. But the beginning of the gestation period is considered to be from the first day of the last menstruation, since at this time the egg future mother starts to mature. At the same time, the hormonal background is changing, such changes in the body occur in order for the egg to simply accept the male principle.

2nd week. During this period, among all the eggs, the one that becomes the leader appears. And in a couple of days the bubble will become larger. Then it will burst and the egg will fall into fallopian tube where it meets the sperm. It is easy for a woman to learn about a breakup, during this period discomfort lower abdomen. This gap is called ovulation. You can keep an ovulation calculator, then it will be easy to calculate exactly when it should come.

3rd week. According to the pregnancy calculator, you have already ovulated and fertilized. This week, the embryo proved its right to exist. At this time, germ cells, the head and coccyx-tail of the baby begin to form. The embryo is implanted in the uterine cavity.

4th week. You can do a test. You already have enough human chorionic gonadotropin. The placenta, umbilical cord and yolk sac begin to form. The height of the child is 0.2 mm, and the weight is 0.5 g.

You have probably already noticed the physical changes that have happened to you, namely:

  • lack of menstruation;
  • the chest is compacted, its sensitivity increases;
  • sometimes you may feel sick, especially morning sickness;
  • change in taste preferences;
  • strong sensitivity to odors, sometimes to the point of irritation.

5th week. This time is considered the end of the term of the first month. The baby is still very small, its length is from 1.5 to 2.5 mm. He feeds on his mother's blood. His heart began to beat. The chord gradually develops, which then becomes the spine, blood vessels begin to depart from the heart, they are not inferior to them in development nervous system and brain. Now on the pregnancy calculator, you can note that your baby is already clearly visible where the arms, legs and head will be.


Many women are already beginning to psychologically feel that a small miracle is growing in them, against this background and against the background of a change in hormones, their mood often changes. The emotional state is often accompanied by: nausea, frequent urination, drowsiness. However, it happens that some future mothers are lucky, and they don’t feel anything like that.

6th week. The embryo develops in the formed fetal bladder, which is now the protection of the child from everything. The heart has already formed and beats at a frequency of 140-150 beats per minute. The length of the embryo is 4-5 mm, weight - 1.3 g. The bases of the legs and arms appear, and small depressions on the head, in which eyes are then formed. The rudiments of the intestines, liver, kidneys, and the immune system are formed.

Throughout the entire pregnancy, you should be very vigilant. But this week is even more so, as you are just getting used to your special state. Go to bed earlier, rest more often, stop walking in heels.

Development of pregnancy in the second half of the first trimester

7th week. On the pregnancy calculator, the seventh week is the middle of the second month. It is impossible to consider it the easiest for the expectant mother. You still have toxicosis, heartburn and bloating have been added to it, your chest has become even larger, and the halo has darkened.


The length of the embryo is 6-9 mm, and the weight is approximately 1.8 g. The head is very large, much larger than the body, and is lowered towards the chest. The arms and legs are already visible. The oral cavity is formed. Eyelids and ears are also formed. The nervous system has practically formed. The heart pumps blood.

8th week. If you keep the calculator not by week, but by day, it turns out that your baby is already 50-56 days old. His height is 1.27 cm, and his weight is 2.1 g. He begins to resemble a baby. The heart completes its formation, its connection with large vessels occurs. The stomach takes the correct position and is in its place. The face begins to form. If it should be a boy, then the testicles are formed.

9th week. The embryo is already almost 3 cm, and its weight is 4 g. The cerebellum is forming. Facial features are slightly different, fingers have formed, and now the baby can bend them. Bones and joints are formed.

If you follow your pregnancy week by week, you should know that this is the time when a large number of miscarriages occur. Such a misfortune happens due to the fact that all the functions corpus luteum takes over the placenta. Of course, if it developed without pathologies, then everything should be fine. But it's best to keep yourself stress-free.

10th week. The child is already moving his limbs, although you do not feel it yet, and may squint, swallow. Nail plates are formed on the fingers, and on the head upper lip and auricles. Milk teeth begin to form (so eat more foods that contain calcium) and genitals.


You, most likely, already have a hard time buttoning up your trousers - you have gained weight. If you do not want to gain too much during pregnancy, but also feed your baby well, then you should eat a balanced diet.

11-week. Fetal growth - 6 cm, weight - 8 g. The baby has grown significantly. He has already formed eyes, ears, nose, mouth. The umbilical cord has formed. Most likely, he already feels with his palms, since his nervous system is practically developed.

On your pregnancy calculator, it is worth noting that in the period from 11 to 13 weeks you should visit a gynecologist in order for him to refer you for tests, such as:

  • blood chemistry;
  • analysis for cytology and flora;
  • if necessary, additional tests.

The first ultrasound is just designed for such a period. It can reveal fetal pathologies and show how many children you will have.

12th week. The height of the baby is 8 cm, and it weighs 14 g. Although the child is still very small and you do not feel it, he actively moves his arms and legs. The mouth can already open and close. The body becomes more like a human body. The sex has not yet been determined, but the fetus can already urinate.

If you follow the pregnancy week by week, then the first trimester is coming to an end. Some people have already lost their nausea. You still have sharp mood swings, but gradually it stabilizes. Remember: any pain, heaviness in the lower abdomen, copious excretion from the vagina should alert you. In this case, you should rest. And if there were bloody issues, contact your doctor immediately. This is a symptom of a miscarriage.

13th week. The baby is still quite tiny: height - 10 cm, weight 15-20 g, but he has already formed all the milk teeth, the intestines begin to contract periodically, the brain takes on the likeness of the brain of an adult. The kid can shake his head.

You finally lost morning sickness, nervousness. You feel much better. Perhaps you want to go back to work. With peace of mind, you can do it. The main thing - do not forget about walking in the fresh air, walk for at least two hours, walk a lot.

Second trimester of pregnancy

The pregnancy calculator shows that the second period of pregnancy has begun.

14th week. The baby has almost all the organs formed, then they will grow with his growth. They begin to perform their functions. The child tries to show the first emotions. Eyebrows begin to grow and the first fluff appears. The placenta nourishes and protects the baby.

Since your uterus has already grown a little, your stomach has become noticeable. She also began to put pressure on the internal organs, so you most likely want to go to the toilet more often, because there is a lot of pressure on the bladder.

15th week. If you touch the abdomen, you will feel that the bottom of the uterus is located 7 cm below the navel. The height of the baby is 13 cm, and the weight is 50 g. The skin of the child is still very thin. This week, the color of future hair begins to be determined. The child can distinguish sounds, listens to his mother's heartbeat, it calms him down. The water in the bubble changes all the time, so in the middle everything remains in a sterile state.

Most likely, you have a dark line on your stomach and darkened halos. Do not worry, all this will pass after childbirth.

16th week. There is a formation of lanugo all over the body of the baby. He has all the signs of a person, down to the eyelashes. Turn on classical music for your child, because he already hears, and pleasant music has a good effect on development.

The pregnancy calculator tells you that a miracle can happen this week and you will finally feel your baby move. Perhaps your memory has deteriorated, but you should not worry about it, the reason for this is the game of hormones.

17th week. Height - 15-16 cm, weight - 140 g. The baby is covered with fluff, the bones begin to harden. Blood vessels are still visible through the skin. The chest rises and falls.

The uterus grew even more. You continue to go to the toilet frequently. Try to avoid people who smoke, smoking is very harmful to the baby. The child takes a lot of your trace elements, including red blood cells, so anemia may occur, then seek help from a doctor.

Second half of the second trimester of pregnancy

18th week. Height - 20-22 cm, weight - 230 g. The growth of the brain continues. Fingers and toes are formed, bones are getting stronger. The placenta serves as a barrier from all troubles. The heart beats even faster, speeding up blood circulation.


If you keep your personal pregnancy calculator, then take it in your hand and mark this week with a red pencil, because this week you can go for an ultrasound and find out the sex of the baby. Now it should look something like in photo 1.

19th week. The child is 24 cm long and weighs 300 g. The baby excretes more and more urine, which then enters the amniotic fluid. He has nephrons. Next, sensory perception develops.

There are many changes in the physical condition of the mother:

  • the amount of secreted whites increases;
  • more frequent indigestion;
  • heartburn appears;
  • legs may swell;
  • pigmentation appears.

But all this fades when you feel the baby move.

mid pregnancy

20th week. A birth lubricant begins to appear on the skin of the child, it protects the still very thin skin of the baby. The first feces produced in the intestines is meconium. Height - 26 cm, weight 320 g.

Your belly keeps growing and your uterus keeps growing, so it might be hard for you to breathe. Your best bet is to sleep on hard surfaces with your feet elevated.

21st week. The child is already swallowing anatomical fluids and may hiccup. The bone marrow develops. Height - 28 cm, weight 400 g.

Already at this time, you may begin to secrete colostrum. Hemorrhoids may appear.

22nd week. The child's skeleton is developing. In your stomach, it moves as it wants: up and down and across. Touches the face, legs, tummy with hands. The skull bones harden.

Choose clothes that will not put pressure on your stomach and prevent you from moving. Do not sit for a long time, as this position is not the best for your back and blood circulation.

23rd week. Height - 30 cm, weight - 530 g. The head has become more proportional in relation to the body. The lungs continue to develop. The spleen and endocrine glands began their work.

You may have improved hair condition, but at the same time, they could begin to grow all over your body. After childbirth, they will disappear. Don't forget about your hygiene.

24th week. Height - 31 cm, weight - 600 g. The formation of the cerebellum is completed. If childbirth begins, then there is a chance that the child will survive, since almost all organs work. The baby is trying to breathe.

You may already be experiencing something similar to contractions, they are called Braxton Hicks contractions. Don't worry about them, they will pass quickly.

25th week. Height - 31 cm, weight - 700 g. The lungs began to secrete surfactant, which allows the pulmonary vesicles not to stick together. The child develops muscle mass. The bone marrow takes on the function of the main circulatory organ.

Your uterus is 25 cm above your womb and is now the size of a soccer ball. It might be dry skin.

26th week. The height of the child is 33 cm, weight is 880 g. This week the brain connects with the adrenal cortex and the endocrine system. The pituitary gland itself produces growth hormone. The baby reacts to light, voice.

The expectant mother should sign up for prenatal courses at the maternity hospital. Try to indulge yourself in order to somehow remove the discomfort.

27th week. The kid has grown a lot. Height - 35 cm, weight - 900 g. He no longer feels as spacious in the uterine cavity as before. The child hears everything and distinguishes the voice. The most favorite for him is the voice of his mother. In boys, the testicles descend into the scrotum.

You have gained 11-13 kg. But don't worry, it's not fat. Everything will be fine after delivery.

Third trimester of pregnancy

28th week. Height - 35 cm, weight - 1110 g. The skin becomes flesh-colored. Lanugo disappears. The kid became very active. It is worth starting to count his pushes. To do this, relax and count the shocks for 10 minutes, if there are not enough of them, then count again. If there are too few or too many movements, immediately go to the doctor.

29th week. Height - 38 cm, weight - 1200 g. The child's body learns to regulate its temperature, the baby is preparing for the birth.

Relax more, please yourself with new dresses for pregnant women.

30th week. Height - 38 cm, weight - 1300 g. At this time, your baby may have turned his head down. Enough light enters the uterus, and the child already distinguishes the difference between light and dark.

Now you can take a vacation. Take care of yourself, get plenty of rest, eat plenty of fruits and vegetables.

31st week. Height - 41 cm, weight - 1600 g. If it so happens that the baby asks for the light right now, it will be considered that you have begun an early full-fledged birth. The baby is gaining muscle mass.

You have pain in your back and pelvis, as well as severe heartburn. To combat this, eat little but often, mineral water and milk also help.

32nd week. Height - 42 cm, weight - 2 kg. The child's wrinkles disappear. Now he often hiccups.

Go to the toilet more often. If you feel cramps in your legs, wiggle your toes a lot. Your gums may be bleeding. Do not worry, everything will pass after the birth.

33rd week. Height - 43 cm, weight - 2100 g. The increase in fat layer continues. The baby falls asleep and wakes up at the same time.

You may experience incontinence when you cough or sneeze heavily. The dark line on the abdomen is getting darker.

34th week. Height - 44 cm, weight - 2400 g. Hair appeared on the head, the skin became light, the nails were already long. The tips of the ears are separated from the head.

Second half of the third trimester of pregnancy

35th week. Height - 46 cm, weight - 2500 g. Now all development consists in gaining weight and height.

Watch your blood pressure. Rest more, drink less.


36th week. Height - 48 cm, weight - 2700 g. The kid is already becoming just like a baby, just a little smaller.

Lubricate the perineum with vitamin E oil so that there are no tears during childbirth.

37th week. Height - 50 cm, weight - 3 kg. Bones and cartilage harden even more. If you count the gestational age by weeks, then it is already complete.

38th week. Height - 50 cm, weight - 3100 g. The kid recovers by 23-30 g every day. The skin is cleansed of lubrication.

You may have stretch marks.

39th week. Height - 51 cm, weight - 3200 g. Vision is three-dimensional and color, the baby sees at a distance of up to 30 cm.

Your uterine fundus has shrunk, it’s hard to walk, breathe, everything is hard. Childbirth soon.

40th week. Height - 52 cm, weight - 3300 g. The child is ready to be born.

Pregnancy is a touching and at the same time exciting period in the life of every family. In anticipation of meeting with the baby, it is important to know what changes are taking place in the body of the mother and baby. Our pregnancy calendar will help with this.

If you are in doubt whether you are pregnant or not, go through.

  • Negative test result? Maybe it's not time yet, try it later.
  • Did the test show a positive result? Congratulations!

In the calendar you will find the most important information and helpful tips. Here you will find out what happens to your baby in every week of pregnancy, in every trimester. The calendar will tell you what feelings a mother may experience during pregnancy, as well as under what conditions you need to be vigilant.

First, the calculator will help calculate the gestational age and the approximate date of delivery. To do this, you need to enter the first day of your last period, as well as the length of your cycle. Recall calculation of the menstrual cycle: you need to take the number of days from the first day of menstruation to last day before the next menstruation (inclusive). Usually averages are taken. A normal menstrual cycle is 28 plus/minus 7 days.

The calendar is divided into 3 stages - trimesters (1 trimester = 3 months). Each trimester includes weeks of pregnancy. Yes, it is in weeks, not months, as many of us are used to, that pregnancy is measured. And mom needs to get used to it, because the gynecologist will calculate the term in this way. In our calendar calculator, the gestational age is also calculated in weeks.

First trimester - 1-12 weeks of pregnancy. This period is the most responsible. The first 2 weeks of pregnancy are theoretical, they are needed for ease of calculation. Fertilization has not yet occurred. But in the third week, the nuclei of the germ cells merge and a small "pea" appears in the tummy. The baby has not yet formed any arms or legs, but from the moment of fertilization it is endowed with a soul. In the first weeks of the first trimester, the mother's immunity decreases so that her body does not perceive the baby as something foreign. Often there are symptoms of toxicosis. By the end of the trimester, the baby looks like a person, only very small. The doctor recommends an ultrasound.

Second trimester - 13-26 weeks of pregnancy. Toxicosis is over, during this period there is less risk for the baby. Mom's tummy is round. Very soon she feels the first tremors - the stirring of the crumbs. Toward the end of the second trimester, it is recommended to repeat the ultrasound examination.

Third trimester - 27-42 weeks of pregnancy. The baby grows, and his "house" also increases. In some cases, it becomes difficult for the mother to breathe, because. the uterus rises very high. It goes away before childbirth. Closer to the cherished day of childbirth, immunity decreases again. So the hormonal background is being rebuilt, preparations are underway for an exciting meeting with the baby.

A baby is considered fully term at 38 weeks of gestation. Most often, childbirth occurs at the 38-40th week, but there are cases when the pregnancy is delayed up to 41-42 weeks. This is quite normal, especially for primiparous mothers. We have included these weeks in the pregnancy calendar so that we can continue to be with you until the birth.

The doctor observes the mother and baby throughout the entire period of pregnancy in order to track the slightest violations and cope with them in time. However, it happens that the mother needs additional information, the opinion of another doctor. The ABC of Health forum will answer your questions.

Enter the first day of your last menstrual period

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As a rule, every pregnant woman has her own calendar, where she enters all the necessary data, outlines important dates, and takes notes. With its help, the gestational age is usually calculated.

Given the nine-month duration of this period, calculations on a piece of paper seem to be a very routine task. But modern women live at a great time - they are not at all obliged to keep such a calendar and do tedious arithmetic, unless, of course, they are so sentimental that they decide to keep their weekly notes as a memory of beautiful time gestation. You can safely entrust the program to take care of calculating the gestational age. After all, for those who prefer to spend their free hours on activities that are much more useful for the future baby and his mother, there are numerous virtual services like this one (we hint at our calculator).

What do you need to calculate the gestational age?

In order to calculate the gestational age right now, you only need to remember the date when the last menstruation began and enter it in the appropriate form fields. This number is the starting point of your pregnancy. We are talking about the so-called "obstetric weeks" - all over the world it is customary to count pregnancy in this way, although fertilization occurs only in the middle of the cycle. This measure is necessary for the convenience of doctors, but often causes surprise and misunderstanding among patients.

It is worth noting that during an ultrasound examination of the fetus, you will come across the fact that the gestational age known to you can be calculated differently - by the weeks of the fetus's life, that is, from the day of conception. You may even find an entry on the ultrasound results sheet that lists both dates. In order not to be embarrassed by such contradictions, feel free to ask the doctors about what period pregnancy is coming speech, real or obstetric?

It is very important to emphasize that even if you know the exact date of conception of the baby, in order to calculate the gestational age using the calculator, you need to use the date of the last menstruation. If you find it difficult to remember, count 2 weeks ago - with a standard 28-day cycle, ovulation most often occurs on day 14.

I don't remember when I had my period. What to do?

Sometimes it happens that a woman does not know when she had her last menstruation, for example, she does not remember, does not follow the regularity of the cycle, she has just stopped taking contraceptives. If you have no idea what your gestational age is, they can calculate it, and quite accurately, at. The most reliable, of course, have the data obtained on early dates, up to 12 weeks, when the rate of development of the fetal egg is still very high and changes are noticeable literally every day. The size of the fetal egg alone, without taking into account the proportions of the fetus, will tell the doctor a lot. For more later dates there may be errors of about 2 weeks.

Another very informative method that allows you to calculate the gestational age is biochemical - a study of a woman's blood for the content of hCG - human chorionic gonadotropin. This hormone is produced fertilized egg and is present in the body only during pregnancy (by the way, it is on its determination in the urine that the well-known instant pregnancy test is based). The content every day and with a healthy pregnancy is clearly correlated with the timing. It is worth noting that this is far from a routine method, requiring a lot of time and financial costs, and it is used mainly for medical reasons.

It is impossible not to mention that finding out the gestational age, calculating and assuming the probable age of the fetus is within the competence of the obstetrician when conducting a vaginal examination in the early stages. The main object of study in this case will be the uterus and palpation (manual) determination of its size. Of course, we are not talking about absolute accuracy, but the data obtained is quite enough to successfully monitor the health of the expectant mother and fetus.

Asking the question of how to calculate the duration of pregnancy, most often women at the same time want to find out the approximate timing of its end. Using this calculator, you can find out the number when you should expect the birth of a baby. However, you may be more comfortable on our other service.

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