Pregnancy Due Date Calculator – EDD from LMP
Calculate your estimated due date (EDD) from your last menstrual period (LMP) or conception date.
❤️ Health📐
Last menstrual period (YYYY-MM-DD)
Please enter valid values.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| Pregnancy Due Date Calculator – EDD from LMP | result |
Step-by-Step Examples
Example 1
LMP March 1, 2024
- Due date: November 5, 2024 (LMP + 280 days = 40 weeks)
✓ November 5, 2024
Example 2
LMP January 15, 2024
- Due date: October 21, 2024
✓ October 21, 2024
Example 3
Conception date +266 days
If you know conception date, add 266 days.
- Conception Feb 14 + 266 = November 6
✓ Conception + 266 days
Real-World Applications
Expecting Mothers
Calculate your estimated due date.
OB/GYN Offices
Quick EDD calculation for patients.
Midwives
Calculate and track pregnancy timeline.
Families
Plan for baby arrival.
Common Mistakes to Avoid
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EDD is an estimate
Only 5% of babies are born on their exact due date. Most births occur within 2 weeks before or after EDD.
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Using conception date vs LMP
LMP is the standard medical calculation. If you know your ovulation/conception date, use LMP method for consistency with healthcare providers.
Frequently Asked Questions
How is EDD calculated? ▾
Naegele's rule: LMP + 280 days (40 weeks). Assumes regular 28-day cycle and ovulation on day 14.
What if my cycle is irregular? ▾
Your OB may adjust the due date based on ultrasound measurements, which are more accurate than LMP in irregular cycles.
When is full-term pregnancy? ▾
39-40 weeks is considered full-term. 37-38 weeks is early term. Under 37 weeks is preterm.