ToolSpotAI

Free Pregnancy Calculator

Calculate your estimated due date using LMP, ultrasound, or IVF transfer date. Track milestones and trimester progress. This tool runs in your browser—no account required.

Health
Date format:

Your Estimated Due Date

Mon, May 10, 2027

🤰 You are 10 weeks pregnantTrimester 1209 days remaining
Week 10 + 1 days25% complete
Week 11st Tri2nd Tri3rd TriWeek 40
🌟

Conception Date

Mon, August 17, 2026

1️⃣

End of 1st Trimester

Mon, November 2, 2026

💪

Viability (Week 24)

Mon, January 18, 2027

2️⃣

End of 2nd Trimester

Mon, February 8, 2027

✅

Full Term (Week 39)

Mon, May 3, 2027

👶

Due Date (Week 40)

Mon, May 10, 2027

Pregnancy Milestones

✓Positive pregnancy test possibleAug 31
✓Heartbeat can be detectedSep 14
✓First prenatal visitSep 28
12End of first trimesterOct 26
13Second trimester beginsNov 2
16Gender may be visible on ultrasoundNov 23
20Anatomy scan (mid-pregnancy ultrasound)Dec 21
24Viability milestoneJan 18
27Third trimester beginsFeb 8
32Baby's lungs maturing rapidlyMar 15
37Early term — baby considered full-termApr 19
39Full termMay 3
40Estimated due date (EDD)May 10
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.

How to Use This Pregnancy Due Date Calculator

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

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.

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.

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