Pregnancy Due Date Calculator

Calculate your estimated due date using LMP, ultrasound, or IVF transfer date. Track milestones and trimester progress.

Health

Date format:

First day of last menstrual period

Your Estimated Due Date

Sat, November 7, 2026

🤰 You are 10 weeks pregnantTrimester 1209 days remaining

Week 10 + 1 days25% complete

Week 11st Tri2nd Tri3rd TriWeek 40

🌟

Conception Date

Sat, February 14, 2026

1️⃣

End of 1st Trimester

Sat, May 2, 2026

💪

Viability (Week 24)

Sat, July 18, 2026

2️⃣

End of 2nd Trimester

Sat, August 8, 2026

✅

Full Term (Week 39)

Sat, October 31, 2026

👶

Due Date (Week 40)

Sat, November 7, 2026

Pregnancy Milestones

✓Positive pregnancy test possible1stFeb 28

✓Heartbeat can be detected1stMar 14

✓First prenatal visit1stMar 28

12End of first trimester1stApr 25

13Second trimester begins2ndMay 2

16Gender may be visible on ultrasound2ndMay 23

20Anatomy scan (mid-pregnancy ultrasound)2ndJun 20

24Viability milestone2ndJul 18

27Third trimester begins3rdAug 8

32Baby's lungs maturing rapidly3rdSep 12

37Early term — baby considered full-term3rdOct 17

39Full term3rdOct 31

40Estimated due date (EDD)3rdNov 7

This calculator provides an estimate only. Only about 5% of babies arrive on their exact due date. Most births occur within 2 weeks before or after. Always consult your healthcare provider.

What is Pregnancy Due Date Calculator?

A pregnancy due date calculator estimates your baby's expected arrival date (EDD — Estimated Date of Delivery). Knowing your due date helps you plan prenatal care, prepare for birth, and track your baby's development week by week. Our calculator supports three methods: Last Menstrual Period (LMP), Ultrasound dating, and IVF transfer date. It displays a trimester progress bar, key milestone dates, and a complete timeline from conception to post-term.

How It Works

Choose your calculation method. For LMP: enter the first day of your last period — the calculator adds 280 days. For ultrasound: enter the scan date and gestational age at that time. For IVF: enter the transfer date and embryo day (3 or 5). The calculator shows your due date, current week, trimester progress, and upcoming milestones.

Formula

LMP Method: Due Date = LMP + 280 days
Ultrasound: Due Date = Scan Date − Days at Scan + 280
IVF Day 5: Due Date = Transfer Date − 19 + 280
IVF Day 3: Due Date = Transfer Date − 17 + 280

Formula Explained

Naegele's rule adds 280 days (40 weeks) from the LMP, assuming ovulation occurs on day 14 of a 28-day cycle. For irregular cycles, ultrasound dating is preferred. IVF calculations work backward from the transfer date to an equivalent LMP date. The gestational age includes the ~2 weeks before conception, which is why pregnancy is "40 weeks" even though fertilization occurs around week 2.

Example

LMP: January 1, 2025 Due Date: October 8, 2025 (280 days later) Current date: April 8, 2025 Gestational age: 13 weeks + 5 days Trimester: Second Progress: 35%

Tips & Best Practices

✓First-trimester ultrasound (6-13 weeks) provides the most accurate dating.
✓If your periods are irregular, tell your provider — LMP dating may be less accurate.
✓The due date is an estimate — prepare for birth anytime from 37-42 weeks.
✓Download a pregnancy tracking app to follow week-by-week development.
✓Most providers recommend 10-15 prenatal visits during pregnancy.

Common Use Cases

•Determining your estimated due date for prenatal planning
•Tracking pregnancy progress week by week
•Planning maternity/paternity leave dates
•Scheduling prenatal appointments and tests
•Understanding fetal development milestones

Frequently Asked Questions

The most common method is Naegele's rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a 28-day cycle with ovulation on day 14. Ultrasound dating in the first trimester is the most accurate method, as early fetal measurements correlate closely with gestational age.

Only about 4-5% of babies are born on their exact due date. Most babies arrive within 2 weeks before or after. First-trimester ultrasound dating is accurate to ±5-7 days. LMP-based dating is accurate to ±2-3 weeks depending on cycle regularity.

First trimester: weeks 1-12 (organ development, morning sickness). Second trimester: weeks 13-26 (growth, movement felt, anatomy scan). Third trimester: weeks 27-40 (weight gain, positioning, preparation for birth). Full term is 37-42 weeks.

For IVF, the due date is calculated from the embryo transfer date. For a Day 5 (blastocyst) transfer, subtract 19 days to get the equivalent LMP date, then add 280 days. For Day 3 transfer, subtract 17 days. This is more accurate than LMP dating because the conception date is known precisely.