Use the Pregnancy Due Date Calculator to estimate* your due date and find out how far along you are. Would you like to know how many days pregnant you are? Are you curious when your baby was conceived and what is your due date? Our Pregnancy Due Date Calculator helps you to find out. You only have to enter the first day of your last period and the length of your cycle (the default value is the most frequent value, 28 days). Based on this date the calculator tells you how long you have been pregnant when the baby was conceived and it also provides an estimation for your due date.
Pregnancy Due Date Calculator
Learn how to use the Pregnancy Calculator
1. How do I use the Pregnancy Due Date Calculator?
First, enter the date of the first day of your last menstrual cycle, followed by the average length of your menstrual cycle (eg, 28). The pregnancy calculator then calculates the estimated date of your pregnancy, also how long you are pregnant, and finally the expected date of delivery.
2. How does the Pregnancy Due Date Calculator works?
With the information provided, we expect an average of 40 weeks or 280 days to become pregnant, which is medically accepted and practically used. It is important that if you have a different menstrual cycle, be sure to change the default value (28) to what is specific to you.
*The dates and values provided below are only approximate values. Real dates may differ. We do not take any responsibility for the correctness of the calculated data. Please also read or Term of Use before using our calculators.
3. What is a Pregnancy Trimester?
Trimester represents an important stage of pregnancy. The first trimester is from week one through 12 and includes conception. During the first trimester, the baby begins to develop, but even at the end of the trimester, it may not have any serious signs. During this period, it is possible that the mother is already suffering from nausea. In the second trimester (4-6 months or 13-28 weeks), mom’s strength returns. During this period, mothers are more desirable. The last 3 trimesters (7-9 months or 29-40 weeks) are the most difficult of all. During this period, energy decreases and fatigue are very common. During this period, mothers must avoid stress and physical exertion.
Pregnancy Timeline
| PREGNANCY TIMELINE | WHAT’S HAPPENING | YOUR BABY (lenght / weight) |
| DAYS 1–14 | The countdown of your pregnancy begins with your period—the start of the fertility cycle. | No baby yet. |
| 2 WEEKS | A mature egg is released from the ovaries and if a sperm fertilizes it, a baby is conceived. | length: approximately 1⁄250 in (0.1 mm) |
| 3 WEEKS | Amazing things are happening inside your body, and some women may experience early signs. | length: > 1⁄32 in (1 mm) |
| 4 WEEKS | If you miss a period this week, it could be the first time you wonder, “Am I pregnant?” | length: 1⁄16 in (2 mm) |
| 5 WEEKS | You won’t be looking pregnant but as your body adapts to the pregnancy, you might well be feeling it. | 1⁄8 in (4 mm) |
| 6 WEEKS | Although there is no visible belly bump, it doesn’t mean your body isn’t changing in other ways. | 3⁄8 in (8 mm) |
| 7 WEEKS | Though you still cannot feel the baby inside you, the heart can be seen beating on an ultrasound now. | 1⁄8 in (1.6 cm), 1⁄32 oz (1 g) |
| 8 WEEKS | As your body adapts to the hormonal changes of pregnancy, you may get sudden mood swings. | 7⁄8 in (2.3 cm), 1⁄16 oz (2 g) |
| 9 WEEKS | Your tiny baby is starting to move around, though you won’t yet be able to feel this exciting action. | 11⁄4 in (3 cm), 1⁄8 oz (4 g) |
| 10 WEEKS | Though not obvious to others, you may start to notice that your body is beginning to look pregnant. | 15⁄8 in (4.1 cm), 1⁄4 oz (7 g) |
| 11 WEEKS | You may see your baby for the first time on your first ultrasound. It’s the start of your love affair! | 21⁄8 in (5.4 cm), 1⁄2 oz (14 g) |
| 12 WEEKS | With nausea and fatigue fading away, you are likely to feel more invigorated. | 27⁄8 in (7.4 cm), 3⁄4 oz (23 g) |
| 13 WEEKS | Changes inside your body mean that you are glowing now. Sit back and enjoy this settled period. | 33⁄8 in (8.7 cm), 11⁄2 oz (43 g) |
| 14 WEEKS | Your pregnancy may be becoming obvious, and you may feel an incredible sense of well-being. | 4 in (10.1 cm), 21⁄2 oz (70 g) |
| 15 WEEKS | It is normal to have mixed feelings about your changing body shape and curves. | 45⁄8 in (11.6 cm), 31⁄2 oz (100 g) |
| 16 WEEKS | You will definitely start to look pregnant now, even if you don’t feel that different. | 51⁄8 in (13 cm), 5 oz (140 g) |
| 17 WEEKS | The bloom of pregnancy may be showing in your skin, and even in your mood. | 55⁄8 in (14.2 cm), 63⁄4 oz (190 g) |
| 18 WEEKS | You may experience your baby’s early, fluttering movements. These are known as “quickening.” | 6 in (15.3 cm), 81⁄2 oz (240 g) |
| 19 WEEKS | You are almost halfway through your journey. Congratulations! | 61⁄2 in (16.4 cm), 101⁄2 oz (300 g) |
| 20 WEEKS | Your ultrasound gives you a glimpse of your well-formed baby. | 101⁄2 in (26.7 cm), 121⁄4 oz (360 g) |
| 21 WEEKS | You are becoming more aware of your lively baby. | 107⁄8 in (27.8 cm), 15 oz (430 g) |
| 22 WEEKS | You may see some unwanted, though usually temporary, side effects. | 113⁄8 in (28.9 cm), 1.1 lb (501 g) |
| 23 WEEKS | Keeping active means you will be well prepared for the birth, and primed for a rapid recovery. | 12 in (30 cm), 1 lb 5 oz (600 g) |
| 24 WEEKS | Your baby might be active when you want to sleep— kicking, yawning, and even hiccupping. | 135⁄8 in (34.6 cm), 1 lb 8 oz (660 g |
| 25 WEEKS | At the close of the second trimester, your thoughts might turn to the birth. | 14 in (35.6 cm), 1 lb 101⁄4 oz (760 g) |
| 26 WEEKS | It’s the home stretch. Your belly is a source of pride, and you will marvel as it grows. | 143⁄8 in (36.6 cm), 1lb 141⁄2 oz (875 g) |
| 27 WEEKS | Reassuringly, babies who are born at this stage in pregnancy have a 90-percent survival rate. | 146⁄8 in (37.6 cm), 2 lb 4 oz (1 kg) |
| 28 WEEKS | At this point, you may not remember how you felt without a belly. | 151⁄8 in (38.6 cm), 2 lb 8 oz (1.2 g) |
| 29 WEEKS | You may start to feel sharp kicks from your baby. | 155⁄8 in (39.9 cm), 3 lb (1.3 kg) |
| 30 WEEKS | Review your birth plan around now. It’s not too late to make changes. | 161⁄8 in (41.1 cm), 3 lb 3 oz (1.5 kg) |
| 31 WEEKS | Your baby may be lying in any number of positions. | 165⁄8 in (42.4 cm), 3 lb 10 oz (1.7 kg) |
| 32 WEEKS | Now is a good time to start thinking about practical preparations. | 171⁄8 in (43.7 cm), 4 lb 31⁄2 oz (1.9 kg) |
| 33 WEEKS | Each day, your baby is preparing for survival in the outside world. | 176⁄8 in (45 cm), 4 lb 111⁄2 oz (2.1 kg) |
| 34 WEEKS | Practicing relaxation techniques will help you prepare for labor. | 181⁄8 in (46.2 cm), 5 lb 5 oz (2.4 kg) |
| 35 WEEKS | Your body is well and truly gearing up for the big day. | 185⁄8 in (47.4 cm), 5 lb 10 oz (2.6 kg) |
| 36 WEEKS | Make sure you have a plan ready for when you go into labor. | 191⁄8 in (48.6 cm) 6 lb 5 oz (2.9 kg) |
| 37 WEEKS | At this point you are probably as big as you are going to get. | 195⁄8 in (49.8 cm), 6 lb 10 oz (3.1 kg) |
| 38 WEEKS | Doublecheck your birth plan; it’s not too late to make changes. | 20 in (50.7 cm), 7 lb 3 oz (3.3 kg) |
| 39 WEEKS | Make sure you are clear on how to recognize the signs of labor. | 201⁄8 in (51.2 cm), 7 lb 11 oz (3.5 kg) |
| 40 WEEKS | Very soon you will be holding your new baby in your arms | 201⁄6 in (51.2 cm), 7 lb 11 oz (3.5 kg) |
source: The Pregnancy Encyclopedia