Calculation Method
First Day of Last Menstrual Period
Enter the first day of your last menstrual period (LMP).
Pregnancy Progress
8
Weeks
0
Days
1
Trimester
20%
Complete
Trimester 1
Weeks 1-12
Trimester 2
Weeks 13-26
Trimester 3
Weeks 27-40
Key Dates
Pregnancy Milestones
Week 6: Heartbeat visible on ultrasound
Oct 7, 2026
Week 12: End of First Trimester
Nov 18, 2026
Week 18: Gender can often be determined
Dec 30, 2026
Week 20: Anatomy scan (mid-pregnancy ultrasound)
Jan 13, 2027
Week 24: Viability milestone
Feb 10, 2027
Week 27: End of Second Trimester
Mar 3, 2027
Week 37: Baby is full term
May 12, 2027
Week 40: Estimated Due Date
Jun 2, 2027
Medical Disclaimer
This calculator provides an estimate only. Only about 5% of babies are born on their due date. Most births occur between 38-42 weeks. Always consult with your healthcare provider for accurate dating and prenatal care. Ultrasound dating performed in the first trimester is generally the most accurate method.
Your Due Date
Estimated Due Date
Jun 2, 2027
Wednesday
Currently
8w 0d
First Trimester
Due Date Scenarios
Explore how changes affect your results
First Trimester Tips
Based on your results
Pregnancy Progress
At 8 weeks and 0 days, you're 20% through your pregnancy with 224 days until your due date.
Due Date Expectations
Only 5% of babies arrive on their due date. 80% are born within 2 weeks of it (38-42 weeks). First-time mothers often deliver closer to 41 weeks.
First Trimester Focus
Early pregnancy is when major organs form. Take prenatal vitamins and avoid harmful substances.
Frequently Asked Questions
How is the due date calculated?
The most common method uses 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. Only about 5% of babies arrive on their exact due date.
What if I conceived through IVF?
For IVF pregnancies, the due date is calculated from the embryo transfer date. For a Day 3 embryo transfer, add 263 days. For a Day 5 (blastocyst) transfer, add 261 days. This is more accurate than LMP dating.
Why might my ultrasound due date differ?
Early ultrasounds (before 12 weeks) can date pregnancy more accurately by measuring the embryo. If there's a difference of more than 7 days from LMP dating, doctors often use the ultrasound date. Later ultrasounds are less accurate for dating.
What is considered full term?
Full term is 39-40 weeks. Early term is 37-38 weeks, late term is 41 weeks, and post-term is 42+ weeks. Babies born between 37-42 weeks are generally considered healthy, though outcomes are best at 39-40 weeks.
How accurate is the estimated due date?
Due dates are estimates. Only about 5% of babies are born on their due date. About 80% are born within 2 weeks of the due date (38-42 weeks). First-time mothers often deliver closer to 41 weeks.
How this works
Formulas are implementations of published clinical or public-health equations. Calculations run in your browser — no inputs are transmitted to our servers and no account is required. The result is informational; it does not diagnose, treat, or replace advice from a clinician.
What this tool can’t do
When to consult a professional
Talk to a licensed healthcare provider before using the output of this tool to make a medical decision, especially if you have an underlying condition, are pregnant, or are on medication that affects metabolism or fluid balance.
Sources
- [1]Centers for Disease Control and Prevention (CDC)Official sourcecdc.govAccessed Apr 21, 2026
- [2]National Institutes of Health (NIH)Official sourcenih.govAccessed Apr 21, 2026
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