When is your
baby due?
Calculate your due date using 5 different methods — Last Period, Due Date, Conception Date, Ultrasound, or IVF Transfer Date. Get your trimester, weeks pregnant, baby size, and milestone tracker instantly.
Last Period (LMP)
Most common method — enter the first day of your last period
Due Date
Already have a due date? Work backwards to see weeks pregnant
Conception Date
Know when you conceived? Get an accurate due date instantly
Ultrasound
Use your scan date and gestational age from the sonographer
IVF Transfer
Supports Day 3, Day 5, and Day 6 embryo transfers
When is your baby due?
Choose your calculation method below
Only on Calculator Planet
5 ways to calculate your due date — which one to use
Most pregnancy calculators only support the Last Period (LMP) method. Ours supports five different methods so you always get an accurate result regardless of what information you have.
Last Period (LMP)
Use when: You know the first day of your last period
Adds 280 days (Naegele's rule) to your LMP date. The most widely used method — your doctor uses this too.
Due Date
Use when: You already have a due date from your doctor
Works backwards 280 days to estimate your LMP, then shows how many weeks pregnant you are today.
Conception Date
Use when: You know the approximate date of conception
Adds 14 days to get the estimated LMP, then adds 280 days for the due date. Useful for planned pregnancies.
Ultrasound Date
Use when: You have a scan report with gestational age
Enter the scan date and how many weeks pregnant you were at the scan. The calculator adjusts the due date based on the sonographer's measurement — more accurate than LMP if your cycles are irregular.
IVF Transfer Date
Use when: You conceived through IVF
Supports Day 3, Day 5, and Day 6 embryo transfers. Each has a different offset because the embryo's age at transfer is already known precisely.
Baby size week by week — fruit & weight comparison
After calculating, you get a live baby size card showing your baby's size compared to a fruit and a tiny animal. Here is the full week-by-week reference:
| Week | Size of a fruit | Length | Weight | Trimester |
|---|---|---|---|---|
| Week 6 | 🫛 Lentil | 0.6 cm | < 1 g | 1st |
| Week 8 | 🍓 Raspberry | 1.6 cm | ~1 g | 1st |
| Week 10 | 🍊 Kumquat | 3.1 cm | ~4 g | 1st |
| Week 12 | 🍋 Lime | 5.4 cm | ~14 g | 1st |
| Week 14 | 🍋 Lemon | 8.7 cm | ~43 g | 2nd |
| Week 16 | 🥑 Avocado | 11.6 cm | ~100 g | 2nd |
| Week 20 | 🍌 Banana | 16.4 cm | ~300 g | 2nd |
| Week 24 | 🌽 Corn | 21.3 cm | ~600 g | 2nd |
| Week 28 | 🍆 Eggplant | 25.0 cm | ~1 kg | 3rd |
| Week 32 | 🎃 Squash | 28.3 cm | ~1.7 kg | 3rd |
| Week 36 | 🍈 Honeydew melon | 32.0 cm | ~2.6 kg | 3rd |
| Week 40 | 🍉 Watermelon | 36.0 cm | ~3.4 kg | 3rd |
Pregnancy milestone tracker — what each chip means
The result shows milestone chips that turn green as you pass each stage. Here is what each one means:
Week 12
1st trimester end
Miscarriage risk drops significantly. Most parents share the news after this point.
Week 20
Anatomy scan
The mid-pregnancy ultrasound checks all major organs and can reveal the baby's sex.
Week 28
3rd trimester begins
Baby's lungs begin maturing. Kick counts become important from this point.
Week 37
Full term
Baby is considered full term. Delivery at this point is safe and expected.
Week 40
Due date 🎉
The estimated due date. Only 5% of babies arrive exactly on this day — a 2-week window either side is normal.
Related tools
Other useful calculators
Pregnancy Term & Due Date
Pregnancy is the period during which one or more offspring develops inside a woman, typically lasting around nine months. Childbirth usually occurs approximately 38 weeks after conception, or about 40 weeks after the last menstrual period (LMP). The World Health Organization (WHO) defines a normal pregnancy term as lasting between 37 and 42 weeks.
During a first OB-GYN visit, a doctor will typically provide an estimated due date based on a sonogram. Alternatively, the due date can be estimated from the date of the last menstrual period using Naegele's rule — adding 280 days (40 weeks) to the first day of the LMP.
While the due date can be estimated, the actual length of pregnancy depends on various factors including the mother's age, length of previous pregnancies, and birth weight. Studies have shown that fewer than 4% of births occur on the exact due date, around 60% occur within a week of the due date, and nearly 90% occur within two weeks. As such, while it is possible to be fairly confident a child will be born within about two weeks of the due date, the exact day of birth cannot be predicted with certainty.
Pregnancy Detection
Pregnancy can be detected either through pregnancy tests or by noticing physical symptoms such as a missed menstrual period, increased basal body temperature, fatigue, nausea, and increased frequency of urination.
Pregnancy tests detect hormones that serve as biomarkers for pregnancy. Clinical blood or urine tests can detect pregnancy as early as six to eight days after fertilisation. Clinical blood tests are more accurate and can detect the hormone hCG (human chorionic gonadotropin, which is only present during pregnancy) earlier and in smaller quantities, though they take more time and are more expensive than home urine tests.
Clinical Blood Test
Most accurate, detects hCG earliest, but more expensive and time-consuming
Clinical Urine Test
Not necessarily more accurate than home tests and may cost more
Home Urine Test
Convenient and affordable; detects pregnancy from around the time of a missed period
Pregnancy Management
Several factors need to be considered during pregnancy, many of which are highly dependent on the individual's situation. Always consult a qualified healthcare provider for personalised guidance.
Medication
Certain medications taken during pregnancy can have lasting effects on the developing fetus. In the United States, the Food and Drug Administration (FDA) classifies drugs into categories A, B, C, D, and X based on potential benefits versus fetal risks. Category A drugs have low risk to the fetus, while Category X drugs have proven significant fetal risks that outweigh any potential benefit to the mother. Anyone who is pregnant should consult their doctor before using any medication.
Weight Gain
Weight gain is a largely inevitable and necessary aspect of pregnancy. It affects fetal development including the weight of the baby, placenta, circulatory fluid, and fat and protein stores. Both insufficient and excessive weight gain can have negative effects for mother and baby, including the need for a caesarean section (C-section) and gestational hypertension.
| Pre-pregnancy BMI | BMI Range | Recommended Weight Gain |
|---|---|---|
| Underweight | < 18.5 | 28 – 40 lbs (13 – 18 kg) |
| Normal weight | 18.5 – 24.9 | 25 – 35 lbs (11 – 16 kg) |
| Overweight | 25 – 29.9 | 15 – 25 lbs (7 – 11 kg) |
| Obese | ≥ 30 | 11 – 20 lbs (5 – 9 kg) |
Based on guidelines from the Institute of Medicine (National Academies of Sciences, Engineering, and Medicine).
Exercise
Research indicates that aerobic exercise during pregnancy can help improve or maintain physical fitness and may reduce the risk of C-sections. Women who exercised regularly before pregnancy and have uncomplicated pregnancies are generally able to continue moderate to high-intensity exercise programs. However, a pregnant person should consult their doctor if any of the following symptoms occur:
- Vaginal bleeding or amniotic fluid leakage
- Shortness of breath, chest pain, or dizziness
- Headache or calf pain and swelling
- Decreased fetal movement or preterm labour
- Muscle weakness affecting balance
Nutrition
Nutrition during pregnancy is particularly important for the health of both mother and baby. Pregnancy increases energy needs and requires specific micronutrients that may not be needed in the same quantities outside of pregnancy.
Folic Acid (Vitamin B9)
Helps reduce the risk of neural tube defects. Recommended before and during early pregnancy.
DHA Omega-3
Essential for brain and retinal development. Infants cannot produce it efficiently and rely on the placenta or breast milk.
Iron
Supports increased blood volume and prevents anaemia in both mother and baby.
Calcium
Supports fetal bone and teeth development. Adequate intake helps protect the mother's bone density.
Pregnant individuals should consult their doctor and/or a registered dietitian to determine the best nutritional plan for their specific needs.
References
- Jukic AM, Baird DD, Weinberg CR, et al. (2013). Length of human pregnancy and contributors to its natural variation. Human Reproduction, 28(10), 2848–2855. PMC3777570.
- Moore K. (2015). How accurate are 'due dates'? BBC News Magazine, February 3, 2015. Available at: bbc.com/news/magazine-31046144
- Institute of Medicine. (2009). Weight Gain During Pregnancy: Reexamining the Guidelines. National Academies Press.
- Davies GA, Wolfe LA, Mottola MF, et al. (2003). Exercise in pregnancy and the postpartum period. Journal of Obstetrics and Gynaecology Canada, 25(6), 516–529.
- Artal R, O'Toole M. (2003). Guidelines of the American College of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period. British Journal of Sports Medicine, 37, 6–12.
- Lammi-Keefe CJ, Couch SC, Philipson E. (2008). Handbook of Nutrition and Pregnancy. Humana Press.