Pregnancy Due Date Calculator India – Baby Birth Date Estimator

Pregnancy Details

First Day of Last Menstrual Period (LMP)

Select the first day of your last period

Average Cycle Length (days)

Average cycle is 28 days. Longer cycles shift the due date later.

Naegele's Rule

Due Date = LMP + 280 days (40 weeks). Conception is assumed around day 14 of your cycle. Actual birth typically occurs between week 38 and 42.

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Select your LMP date above to see your expected due date

The Three Trimesters

First Trimester (Weeks 1–12)

Baby's organs and systems begin forming. Morning sickness is common. Critical period for fetal development. First ultrasound recommended at 8–12 weeks.

Second Trimester (Weeks 13–26)

Baby's movements become noticeable (quickening). Energy levels improve. Anatomy scan at 18–20 weeks. Baby develops hearing and can respond to sounds.

Third Trimester (Weeks 27–40)

Rapid weight gain. Baby's lungs mature. Frequent check-ups. Baby settles into birth position. Most deliveries happen between weeks 38–42.

Important Pregnancy Tips

→Folic acid — take 400mcg/day from the time you plan to conceive through the first 12 weeks to prevent neural tube defects.
→First ANC visit — schedule your first antenatal check-up within 8–10 weeks of pregnancy confirmation.
→Due dates vary — only about 5% of babies arrive exactly on the due date. A range of ±2 weeks (38–42 weeks) is completely normal.
→Always consult your doctor — use this calculator as a guide. Your OB/GYN will confirm your dates via ultrasound.

How Your Due Date Is Calculated

The standard method is Naegele's Rule, used by doctors worldwide. It counts 280 days (40 weeks) from the first day of your Last Menstrual Period (LMP):

EDD = LMP + 280 days
or: LMP − 3 months + 7 days + 1 year

Example

LMP = 1 Jan 2026 → EDD = 8 Oct 2026 (1 Jan + 280 days).

If your cycle isn't 28 days, the calculator adjusts by adding (cycle length − 28) days, since ovulation shifts with cycle length.

Other Ways to Date a Pregnancy

→Ultrasound dating — a first-trimester scan (crown-rump length) is the most accurate method, usually within ±5 days, and your doctor may revise the EDD based on it.
→Conception date — if you know your ovulation/conception date, add 266 days instead of 280.
→IVF transfer — for a Day-5 embryo, EDD = transfer date + 261 days; for a Day-3 embryo, + 263 days.
→Fundal height — in later pregnancy, doctors cross-check growth by measuring the uterus, though it is only a rough guide.

Frequently Asked Questions

Common questions about pregnancy due dates

How accurate is the due date calculator?

This calculator uses Naegele's Rule (LMP + 280 days), the standard used by doctors worldwide. It assumes a regular 28-day cycle. For irregular cycles, adjust the cycle length. Your doctor may revise the EDD based on your first trimester ultrasound, which is the most accurate dating method.

What is the difference between LMP and conception date?

LMP (Last Menstrual Period) is the standard start point for pregnancy dating. Conception happens approximately 14 days after LMP (at ovulation). Pregnancy is conventionally counted from LMP (40 weeks total), even though conception occurs about 2 weeks later (so the fetus is actually 38 weeks old at birth).

What week is full term pregnancy?

Full term is defined as 39 to 40 weeks 6 days. Early term is 37–38 weeks 6 days. Late term is 41–41 weeks 6 days. Post term is 42+ weeks. Preterm (premature) is before 37 weeks.

When should I schedule my first doctor visit?

Schedule your first prenatal (antenatal care / ANC) appointment as soon as you confirm your pregnancy, ideally by 8 weeks. Your doctor will confirm the pregnancy, estimate your due date via ultrasound, and recommend blood tests and supplements like folic acid and iron.

Can I calculate my due date from conception or IVF date?

Yes. If you know the conception (ovulation) date, add 266 days instead of 280. For IVF, the EDD is the transfer date plus 261 days for a Day-5 (blastocyst) embryo, or plus 263 days for a Day-3 embryo. These methods are often more precise than LMP-based dating.

What if my menstrual cycle isn't 28 days?

Naegele's Rule assumes a 28-day cycle with ovulation on day 14. If your cycle is longer or shorter, ovulation shifts, so the calculator adds (cycle length − 28) days to the estimate. For a 32-day cycle it adds 4 days; for a 25-day cycle it subtracts 3. Enter your usual cycle length for a closer estimate.

How do pregnancy weeks convert to months?

Pregnancy is tracked in weeks because months vary in length. As a guide: month 1 = weeks 1–4, month 3 ends around week 13, month 6 around week 27, and month 9 runs to week 40. Doctors and apps almost always use the week count, which is more precise.

Is it normal to deliver before or after the due date?

Completely normal. Only about 5% of babies arrive exactly on the due date; most are born any time between 38 and 42 weeks. The EDD is a midpoint estimate, not a deadline. If you go past 41 weeks, your doctor will monitor more closely and may discuss induction.