Due Date Calculator
- Resources
- Due Date Calculator
Due Date Calculator Curious to Know Your Estimated Due Date?
Our easy-to-use pregnancy calculator is the number one most popular way to calculate your due date based on the date of your last menstrual period or conception date, IVF transfer date, or the date of your last ultrasound. By entering either of these dates, the calculator provides a reliable estimate of your due date, helping you track your pregnancy with ease.
Due Date Calculator
Your baby is due:
Oct08
Estimated Date of Conception: Jan 15, 2022
(242 weeks + 3 days or 60 months)
This is based on the cycle length provided, not an average cycle length of 28 days, however it is still an estimate.You are 607% of the way through your pregnancy.
607%
Weekly Development
Week 1 & 2
Weeks 1 & 2 of your pregnancy is Jan 02, 2022 - Jan 15, 2022
Baby Conceived
It's ovulation time. If sperm and egg meet, you're on your way to pregnancy.
Week 3
Week 3 of your pregnancy is Jan 16, 2022 - Jan 22, 2022
Implantation occurs
Your baby is a tiny ball of several hundred cells that are rapidly multiplying and burrowing into the lining of your uterus. The cells that become the placenta are producing hCG, the pregnancy hormone. It tells your ovaries to stop releasing eggs and keep producing progesterone. Once there's enough hCG in your urine, you'll get a positive pregnancy test result.
Week 4
Week 4 of your pregnancy is Jan 23, 2022 - Jan 29, 2022
Positive Pregnancy Test
Your baby is an embryo made up of two layers, the hypoblast and the epiblast. The primative placenta is developing and preparing to provide nutrients and oxygen to your growing baby. The amniotic sac is developing and will surround and protect your baby while it continues to grow.
Week 5
Week 5 of your pregnancy is Jan 30, 2022 - Feb 05, 2022
Your embryo is now made up of three layers, the ectoderm, the mesoderm and the endoderm which will later form all the organs and tissues. You might start to feel the first twinges of pregnancy such as tender breasts, frequent urination, or morning sickness
Week 6
Week 6 of your pregnancy is Feb 06, 2022 - Feb 12, 2022
Heartbeat detectable by ultrasound
Your baby's heart is beating about 160 times a minute and the nose, mouth and ears are taking shape. Lungs and digestive system are forming organs.
Week 7
Week 7 of your pregnancy is Feb 13, 2022 - Feb 19, 2022
Your baby is forming hands and feet. Key organs like the stomach, liver and esophagus are beginning to form. Your uterus has doubled in size. The umbilical cord is transferring blood and waste between baby and mother.
Week 8
Week 8 of your pregnancy is Feb 20, 2022 - Feb 26, 2022
The respiratory system is forming now. Breathing tubes extend from the throat to the branches of the developing lungs.
Week 9
Week 9 of your pregnancy is Feb 27, 2022 - Mar 05, 2022
Your baby is nearly an inch long now. If you watch closely, you may see your baby move if you have an ultrasound done
Week 10
Week 10 of your pregnancy is Mar 06, 2022 - Mar 12, 2022
Your baby's organs are growing and beginning to mature. The baby's head comprises half the length of the body.
Week 11
Week 11 of your pregnancy is Mar 13, 2022 - Mar 19, 2022
Fingers and toes have separated and the bones are beginning to harden. External genitalia has almost completely formed.
Week 12
Week 12 of your pregnancy is Mar 20, 2022 - Mar 26, 2022
The kidneys can now secrete urine and the nervous system is maturing. You baby may be curling all 10 toes, practicing opening and closing fingers and sucking a thumb. And mom should have gained from 2-5 lbs.
Week 13
Week 13 of your pregnancy is Mar 27, 2022 - Apr 02, 2022
Miscarrige risk decreases
Your baby now has unique fingerprints and the kidney and urinary tract are completely functional, that means she's peeing. And if you are having a girl, her ovaries are already full of thousands of eggs.
Week 14
Week 14 of your pregnancy is Apr 03, 2022 - Apr 09, 2022
Your baby's facial muscles are getting a workout as he squints, frowns, grimaces and practices his first smile for you.
Week 15
Week 15 of your pregnancy is Apr 10, 2022 - Apr 16, 2022
Your baby is looking more like a baby with legs growing longer than the arms and all her limbs moving. The ears are properly positioned on the side of her head and the eyes are moving from the side of the head to the front of the face.At your doctor's visit, he should offer you a quad screening test to check for Down's syndrome or other chromosomal abnormalities.
Week 16
Week 16 of your pregnancy is Apr 17, 2022 - Apr 23, 2022
Baby's heart is pumping about 25 quarts of blood each day. His eyes are working and moving side to side even though the eyelids are still sealed. Mom will have a "pregnancy glow" due to increased blood supply.
Week 17
Week 17 of your pregnancy is Apr 24, 2022 - Apr 30, 2022
Baby's skeleton is changing from soft cartilage to bone and her heart is now regulated by her brain. She's practicing her sucking and swallowing skills in preparation for that first suckle at your breast or the bottle. Mom's breasts may have increased a full bra size.
Week 18
Week 18 of your pregnancy is May 01, 2022 - May 07, 2022
Gender reveal time
If you're having a girl, her uterus and fallopian tubes are formed and in place. If you're having a boy, his genitals are noticable now but he may hide them during an ultrasound. Are you feeling kickes and punches? Baby's hearing is also developing, so you may want to start talking to your baby.
Week 19
Week 19 of your pregnancy is May 08, 2022 - May 14, 2022
Baby's brain is designating specialized areas for his 5 senses - vision, hearing, taste, smell and touch. A waxy protective coating called the vernix caseosa is forming on his skin to prevent wrinkling.
Week 20
Week 20 of your pregnancy is May 15, 2022 - May 21, 2022
Your baby weighs about 10 ounces and is the size of a small banana. Her uterus is fully formed this week and she may have tiny primitive eggs in tiny ovaries now. His testicles are waiting for the scrotum to finish growing and will begin their descent soon. Mom can expect to gain about 1/2 lb per week for the rest of her pregnancy.
Week 21
Week 21 of your pregnancy is May 22, 2022 - May 28, 2022
Feel all that moving and shaking going on! Baby's arms and legs are in proportion now and movements are much more coordinated. Bone marrow is now helping the liver and spleen produce blood cells. The intestines are starting to produce meconium, the thick tarry looking stool first seen in baby's diaper.
Week 22
Week 22 of your pregnancy is May 29, 2022 - Jun 04, 2022
Senses are growing stronger. Now she can hear your heart beat, your breathing and digestion. Sense of sight is becoming more fine-tuned and he can preceive light and dark. Hormones are now developing which will the organs the commands they need to operate.
Week 23
Week 23 of your pregnancy is Jun 05, 2022 - Jun 11, 2022
Premature baby may survive
Baby's organs and bones are visible through his skin, which has a red hue because of the developing veins and arteries beneath. He'll become less transparent as his fat deposits fill in. Baby is also developing surfactant which will help the lungs inflate if baby is born prematurely
Week 24
Week 24 of your pregnancy is Jun 12, 2022 - Jun 18, 2022
Baby's face is almost fully formed complete with eyelashes, eyebrows and hair. Right now her hair is white because there's no pigment yet. Between now and 28 weeks, the doctor should send mom for a glucose screening test for gestational diabetes.
Week 25
Week 25 of your pregnancy is Jun 19, 2022 - Jun 25, 2022
Baby is gaining more fat and looking more like a newborn. Hair color and texture is in place. His lungs are maturing and preparing for that first breath. You might feel the baby having hiccups.
Week 26
Week 26 of your pregnancy is Jun 26, 2022 - Jul 02, 2022
Brain-wave activity is on high That means baby can hear noises and respond to them with an increase pulse rate or movement. Eyes are beginning to open but they don't have much pigmentation. That will develop over the next couple months and may even continue to change until she's about 6-months-old.
Week 27
Week 27 of your pregnancy is Jul 03, 2022 - Jul 09, 2022
Start talking to your baby
Baby may recognize both your and your partner's voices. This is the time to read and even sing to your baby. She now has taste buds so when you eat spicy food, your baby will be able to taste the difference in the amniotic fluid. Her mealtime comes about two hours after yours. Feel some belly spasms? Those are likely hiccups from that spicy food. It doesn't bother the baby as much as you. Baby also has settled in to a regular sleep cycle, but it may be different from mom's.
Week 28
Week 28 of your pregnancy is Jul 10, 2022 - Jul 16, 2022
During the third trimester the brain triples in weight adding billions of new nerve cells. Senses of hearing, smell and touch are developed and functional. Your baby is having different sleep cycles, including rapid eye movement. That means she's dreaming.
Week 29
Week 29 of your pregnancy is Jul 17, 2022 - Jul 23, 2022
Baby can breathe
Baby's bones are soaking up lots of calcium as they harden so be sure to consume good sources of calcium. We recommend taking Nordic Naturals and Fairhaven Health supplements.
Week 30
Week 30 of your pregnancy is Jul 24, 2022 - Jul 30, 2022
Baby's brain is taking on characteristic grooves and indentations to allow for an increased amount of brain tissue. Bone marrow has taken over the production of red blood cells. This means she'll be better able to thrive on her own when she's born Baby is now weighing about 3 lbs and is 11 inches.
Week 31
Week 31 of your pregnancy is Jul 31, 2022 - Aug 06, 2022
Baby's brain is developing faster than ever and he's processing information, tracking light and perceiving signals from all five sense. She's probably moving a lot, especially at night when you're trying to sleep. Take comfort that all this activity means your baby is healthy. Mom may start feeling some Braxton Hicks contractions.
Week 32
Week 32 of your pregnancy is Aug 07, 2022 - Aug 13, 2022
Baby can focus on large objects not too far away; toenails and fingernails have grown in along with real hair. He's practicing swallowing, breathing, kicking and sucking. All key skills for thriving after birth.
Week 33
Week 33 of your pregnancy is Aug 14, 2022 - Aug 20, 2022
Immune system is maturing
The bones in your baby's skull are still pliable which makes it easier for her to fit through the birth canal. Your uterine walls are becoming thinner allowing more light to penetrate your womb. That helps baby differentiate between night and day.
Week 34
Week 34 of your pregnancy is Aug 21, 2022 - Aug 27, 2022
Baby's fat layers are filling her out and will help regulate body temperture when she's born. If your baby is a boy, the testicles are making their way down from the abdomen to the scrotum.
Week 35
Week 35 of your pregnancy is Aug 28, 2022 - Sep 03, 2022
Kidneys are fully developed and her liver can process some waste products. Most of her physical development is complete. She'll spend the next few weeks gaining weight and adding baby fat. Baby is settling lower into the pelvis preparing for delivery and this is called "lightening".
Week 36
Week 36 of your pregnancy is Sep 04, 2022 - Sep 10, 2022
Hopefully your baby is in a head-down position. If not, your practitioner may suggest an external cephalic version to manipulate your baby into a head down position. The vernix caseosa has now disappeared.
Week 37
Week 37 of your pregnancy is Sep 11, 2022 - Sep 17, 2022
Baby is considered full term
Baby is taking up most of the room in your womb so he's only kicking and poking you, no more somersaults. Baby is sucking her thumb, blinking eyes and inhaling and exhaling amniotic fluid.
Week 38
Week 38 of your pregnancy is Sep 18, 2022 - Sep 24, 2022
Baby's eyes right now are blue, gray or brown but once they're exposed to light they may change color or a shade. The lanugo, the fine downy hair that covered his body for warmth is falling off in preparation for delivery. Her lungs have strenthened and her vocal cords have developed. That means she's ready for her first cry.
Week 39
Week 39 of your pregnancy is Sep 25, 2022 - Oct 01, 2022
Baby is ready to make his debut. He's adding more fat as his pinkish skin turns white or white-grayish. He won't have his final pigment until shortly after birth.
Week 40
Week 40 of your pregnancy is Oct 02, 2022 - Oct 08, 2022
This is the official end of your pregnancy but because due dates are just a calculation he might be "late." No need to worry, your body knows the right time to go into labor, or your doctor may suggest you be induced. At birth your baby's eye sight is a little blurry since central vision is still developing. Just say hello and he'll recognize your voice.
Pregnancy Milestones
After fertilization and implantation, your baby is just an embryo, that is a set of cells from which all organs and body parts will develop. It will be exciting to see how fast your baby grows.
At the beginning of the second trimester, your baby is about 3 1/2 inches long and weigh about 1 1/2 ounces. Tiny, unique fingerprints are now in place, and the heart pumps 25 quarts of blood a day. As the weeks go by, your baby's skeleton starts to harden from rubbery cartilage to bone, and he or she develops the ability to hear. You're likely to feel kicks and flutters soon if you haven't already.
By the end of the second trimester, your baby is about 14-1/2 inches and weighing around 2 pounds.
Pregnancy Calendar and Due Date Calculator
- Share This Tool:
- Share This Tool:
Featured Video
Check Out More Videos
Pregnancy Playlists
Featured Video
Check Out More Videos
- Unplanned Pregnancy
- Getting Pregnant
- Healthy Pregnancy
- Giving Birth
- Postpartum
Frequently Asked Questions
How is my estimated due date calculated?
Calculated by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP), this standard clinical method provides a helpful baseline for your journey. This approach assumes a 28-day cycle with ovulation at the midpoint. While this is the most common starting point, your healthcare provider may refine this date based on early ultrasound measurements.
What if I don’t know the date of my last period?
When menstrual cycles are irregular or the last period date is unknown, a dating ultrasound is used to determine an accurate due date. This clinical scan measures the baby’s length to establish a precise pregnancy timeline. Understanding your timeline early can provide significant peace of mind as you begin planning your prenatal care.
How accurate is an estimated due date?
An estimated due date is a helpful target, but only about 5% of babies are born on their exact date. It is natural to feel eager for your baby’s arrival, so it helps to view this date as a window rather than a fixed deadline. Most healthy pregnancies delivered between 37 and 42 weeks are considered full-term.
Can my due date change during pregnancy?
Yes, a due date may be adjusted during the first trimester as more clinical data becomes available. As your baby grows, ultrasound measurements provide a more precise view of development than a calendar alone. Your provider will update your roadmap to ensure you receive the most accurate and compassionate care at every stage.
How many weeks pregnant am I today?
Pregnancy is measured in gestational weeks starting from the first day of your last period, rather than the day of conception. This clinical standard means you are technically considered “two weeks pregnant” before conception occurs. Understanding this helps you align your personal timeline with your doctor’s prenatal appointment schedule.
Track Your Baby's Development
Subscribe to our week-by-week Pregnancy Newsletter
Free Pregnancy Resources are Available for You
Whether you are trying to get pregnant, are pregnant, preparing to give birth or have an infant the Pregnancy Questions Center is a trusted resource for the most important questions. The Pregnancy Questions Center is easy to use with quick answers and articles. We listened and each question came from someone just like you.
Did You Get a Positive Test? You Are Not Alone!
Speak or chat to a real person about your pregnancy, click the Chat Now button in the lower right corner or feel free to call our toll free helpline below.
Free: Live Helpline
1-800-672-2296
How Can My Estimated Due Date Be Calculated?
When estimating your due date, several methods can be used. The method you choose depends on the available information and your specific circumstances. Expand to see the primary ways of calculating your pregnancy due date.
This official page is maintained and verified by the APA Content Validation Team.
Last Revision: June 1, 2026
Last Menstrual Period (LMP)
The Last Menstrual Period (LMP) method is the most commonly used method to estimate a due date. It calculates your due date by counting 40 weeks (280 days) from the first day of your last menstrual period. This method assumes a regular 28-day cycle and ovulation occurring around day 14 of your cycle. It’s simple and widely used but may not be as accurate for women with irregular cycles or those who don’t ovulate on day 14.
To calculate your due date using LMP:
- Start with the first day of your last period.
- Add 280 days (or 9 months and 7 days).
While this method is effective for many women, it may not be suitable for those with cycle lengths longer or shorter than 28 days. For instance, women with longer cycles may ovulate later, which means their due date will need adjustment.
Conception Date
If you have been tracking ovulation or using ovulation test strips for recognizing your ovulation window, the Conception Date Method is a more accurate way to estimate your due date. This method adds 266 days (or approximately 38 weeks) to the date of conception. It is most accurate for women who have tracked ovulation closely or for those who know the exact date of conception (often through fertility treatments like IUI).
This method is particularly useful for women with irregular cycles or who have tracked ovulation through various methods like basal body temperature or ovulation predictor kits.
IVF Transfer Date Method
For women who conceive through In Vitro Fertilization (IVF), the IVF Transfer Date method is highly precise. This method uses the exact date of the embryo transfer to calculate the due date, as the transfer date is known with certainty.
- Day-three embryo transfer: If your transfer was on day three, your due date is calculated by adding 263 days from the transfer date.
- Day-five embryo transfer: If your transfer was on day five, your due date is calculated by adding 261 days.
IVF offers a very accurate calculation because the exact date of conception (embryo transfer) is known, eliminating any uncertainties associated with menstrual cycles or ovulation dates.
Ultrasound Scan
An Ultrasound scan is a reliable method for determining the due date, especially if you can’t pinpoint the date of conception or your last menstrual period. Early ultrasounds, typically taken in the first trimester, are most accurate for estimating the due date as they measure the size of the fetus, especially in the first 12 weeks.
In early pregnancy, ultrasound measurements of the fetus can often give a more accurate due date than LMP, especially for women with irregular cycles, those unsure of ovulation timing, or those who have longer or shorter cycles. If your due date is uncertain or if you have irregular periods, an ultrasound can be a helpful tool to confirm or adjust your estimated due date.
How Accurate is My Pregnancy Due Date?
Estimating your due date is an important part of pregnancy planning, but it’s essential to remember that it is an estimate. While the calculation can provide a general idea of when you can expect to give birth, the exact timing can vary for several reasons.
Several factors influence the accuracy of your due date, including cycle length, the method used, and any individual differences, such as IVF procedures or the timing of your ultrasound. For instance, the Last Menstrual Period (LMP) method assumes a 28-day cycle, which may not apply to women with shorter or longer cycles. Women with irregular cycles or those who don’t ovulate on day 14 may experience discrepancies between their calculated and actual due date. On the other hand, IVF and ultrasound methods tend to offer more precise due date estimates, as these are based on specific, trackable events like embryo transfer dates or early fetal measurements.
In general, while due dates are not guaranteed, they are still reliable and can help guide your preparations. Most pregnancies are delivered within a week or two before or after the estimated due date, with only about 5% of babies actually being born on their exact due date.
Can My Due Date Change?
Yes, due dates can change during pregnancy. For example, an ultrasound may adjust a due date because of the increased accuracy of using fetal measurements or if your cycle is longer or shorter than 28 days this can lead to a due date adjustment as well. While a Due Date Calculation provides a helpful general estimate, the actual due date may shift as new information becomes available or through the natural variability in the growth of each baby during pregnancy.
What If I Already Know My Due Date?
Even if you already know your due date, Our Pregnancy Due Date Calculator can still be incredibly helpful. By entering your known due date the Pregnancy Due Date Calculator can provide you with a detailed pregnancy timeline, outlining key milestones and symptoms, important prenatal tests, or reminders for prenatal visits based on your known due date.
Top Tools
Featured Video
Pregnancy Journeys
Whenever you’re ready, feel free to explore our other journeys for support at every stage of pregnancy.
Top Resources
You’re Never Alone on Your Journey
No matter where you are in your pregnancy
journey, you’ll always have our support.
- Free: Live Helpline
- 1-800-672-2296
