Calculate your estimated due date using Naegele's rule based on your last menstrual period or conception date. This free due date calculator shows your due date, conception date, current week of pregnancy, and trimester information.
Select the first day of your last menstrual period (LMP) using the date picker. This is the most common method for estimating due dates.
Enter your average menstrual cycle length in days (typically 28 days). You can adjust this between 20-45 days for a more personalized result.
Click Calculate to see your estimated due date, conception date, current pregnancy week, fertile window, and trimester information all at once.
Q: How accurate is the due date calculation?
A: Naegele's rule estimates that pregnancy lasts approximately 280 days (40 weeks) from the first day of the LMP. Only about 5% of babies are born exactly on the due date.
Q: What if my cycle is irregular?
A: You can adjust the cycle length field. However, for irregular cycles, the due date is less precise. Consult your healthcare provider for a more accurate assessment.
Q: Can the due date change?
A: Yes, due dates can be adjusted based on early ultrasound measurements, especially in the first trimester. This calculator uses Naegele's rule as a starting point.