Due Date Calculator
Estimate your due date from the first day of your last menstrual period (LMP).
What is Due Date?
The estimated due date (EDD) is approximately 280 days (40 weeks) after the first day of your last menstrual period.
How is it calculated?
Naegele's rule: EDD = LMP + 280 days. Accuracy is best when cycles are regular and approximately 28 days long.
Frequently Asked Questions
- How accurate is this?
- Only ~5% of babies arrive exactly on the EDD. Most are born within 2 weeks before or after.