Find your baby’s due date by last period, conception date, IVF transfer, or ultrasound.
When is your baby due? Use this pregnancy calculator to find your due date based on the date of your last menstrual period, conception date, IVF three-day or five-day transfer date, or date of your last ultrasound.
Congratulations! You are week pregnant.
1st Trimester2nd Trimester3rd Trimester
👶
Fetal Development 👶
This calculator provides estimated dates only. Always consult your healthcare provider for accurate pregnancy dating and medical advice.
To find how many weeks pregnant you are, count from the first day of your last menstrual period (LMP) to today.
For example, if your last period started 10 weeks ago, you are 10 weeks pregnant.
Use the calculator above — it automatically shows your current week of pregnancy along with your due date.
Here is a quick reference:
If LMP Was…
You Are Approximately…
4 weeks ago
4 weeks pregnant (1st trimester)
8 weeks ago
8 weeks pregnant (1st trimester)
12 weeks ago
12 weeks pregnant (end of 1st trimester)
16 weeks ago
16 weeks pregnant (2nd trimester)
20 weeks ago
20 weeks pregnant (halfway)
28 weeks ago
28 weeks pregnant (3rd trimester)
36 weeks ago
36 weeks pregnant (near full term)
Full term is considered 39–40 weeks. Babies born between 37–42 weeks are considered term pregnancies.
What is an Estimated Due Date (EDD)?
An estimated due date (EDD) is the date when your baby is expected to be born. It is usually 40 weeks (280 days) from the first day of your last menstrual period. Only about 5% of babies are born on their exact due date, but most arrive within a two-week window on either side.
How is Due Date Calculated?
This is the most common method used by doctors in India and worldwide. If your cycle is longer or shorter than 28 days, this calculator automatically adjusts the due date.
1. From the Last Menstrual Period (LMP)
The most common method is Naegele’s rule:
Take the first day of your last menstrual period
Add 1 year
Subtract 3 months
Add 7 days
This assumes a 28-day cycle. Adjustments may be made for shorter or longer cycles.
2. From Conception Date
If you know the exact conception date, add 266 days (38 weeks). This can be more accurate, especially if you were tracking ovulation or used assisted reproduction.
3. For IVF Pregnancies
Because embryo transfer dates are exact, IVF due dates are calculated as:
3-day transfer → add 263 days
5-day transfer → add 261 days
4. Using Ultrasound Scans
Ultrasounds (especially in the first trimester) can estimate gestational age by measuring crown-rump length or other growth markers. If ultrasound results differ significantly from LMP dates, doctors may adjust your due date.
Can My Due Date Change?
Yes. Your provider may revise it if:
You have irregular cycles
The LMP date is uncertain
Early ultrasound results differ significantly
Multiple pregnancies are discovered
Once confirmed by an early ultrasound, due dates usually remain unchanged.
Can I Plan My Due Date?
It’s possible to plan the season of birth by timing conception, but exact dates are unpredictable. Ovulation timing, sperm survival, implantation, and natural variation in pregnancy all play a role. The only way to guarantee a specific date is through a medically scheduled induction or cesarean section.
What Happens in Each Trimester?
First Trimester (Weeks 1–12)
The first trimester runs from week 1 to week 12 — the most critical period for fetal development.
The second trimester (weeks 13–26) is often called the “honeymoon period” of pregnancy — symptoms ease and energy returns.
Baby’s movements (“quickening”) felt
Gender may be visible on ultrasound
Energy levels often improve
Third Trimester (Weeks 27–40)
The third trimester (weeks 27–40) is the final stretch. Most hospitals in India schedule delivery between weeks 38–40.
Baby gains weight rapidly
Brain and lung development continue
Baby usually moves head-down
Mother may feel more discomfort, Braxton Hicks, sleep issues
Key Pregnancy Milestones by Week
Week
Milestone
Week 6
Heartbeat detectable on ultrasound
Week 8
All major organs forming
Week 12
End of first trimester — miscarriage risk drops
Week 16
Baby’s gender may be visible
Week 20
Anatomy scan (anomaly scan) recommended
Week 24
Baby reaches viability milestone
Week 28
Third trimester begins
Week 32
Baby’s lungs developing rapidly
Week 36
Considered late preterm
Week 40
Full term — estimated due date
Your doctor may schedule specific tests and scans at these key weeks. Use your due date to plan ahead for each milestone.
How You Can Use This Information
Track pregnancy milestones
Schedule prenatal checkups and tests
Prepare for your baby’s arrival with more confidence
FAQs
Due date calculators based on LMP are accurate within 1–2 weeks for women with regular 28-day cycles. First trimester ultrasounds (before 12 weeks) are the most accurate method — typically within 5–7 days. Most doctors use a combination of LMP date and early ultrasound to confirm the due date.
Count from the first day of your last menstrual period to today. Each 7 days = 1 week of pregnancy. At 4 weeks, your period is just due. At 8 weeks, you are 2 months pregnant. Use the calculator above for an instant answer.
Pregnancy is counted as 40 weeks from LMP, which is approximately 9 months and 1 week. The confusion arises because calendar months vary in length. Doctors count in weeks — 40 weeks is considered full term.
Yes. If your first trimester ultrasound shows a gestational age that differs by more than 7 days from your LMP date, your doctor may revise your due date. After 20 weeks, due dates are rarely changed as ultrasound measurements become less precise.
In IVF pregnancies, the transfer date is exact, so due dates are more precise. For a 3-day embryo transfer, add 263 days. For a 5-day transfer, add 261 days. This calculator handles both automatically — select IVF Transfer method above.
Full term in India, as per standard obstetric guidelines, is 39–40 weeks. Babies born between 37–38 weeks are early term, and those born at 41+ weeks are late term. Most hospitals in India recommend delivery by 40–41 weeks to avoid complications.
