🤰 Pregnancy Due Date Calculator
Check your estimated due date and current week of pregnancy from your last menstrual period
Enter Last Period Start Date
Estimated Due Date
2027.02.17
Current Week of Pregnancy
10w 0d
Time Until Due Date
210 days left
Due Date Formula
This calculator uses Naegele's Rule. Due date = first day of last menstrual period + 280 days (40 weeks). This assumes a 28-day menstrual cycle; the actual ovulation date or a different cycle length can shift the estimate by a few days.
Example
If the first day of your last period was May 12, 2026, your estimated due date is around February 16, 2027.
Frequently Asked Questions
Q. Can the actual birth date differ from the due date?
A. Yes. The due date is a statistical average, and most births occur within about 2 weeks before or after it.
Q. What if my cycle isn't 28 days?
A. Naegele's Rule assumes a 28-day cycle, so if your cycle is longer or shorter, an ultrasound-based estimate from your doctor based on the actual ovulation date will be more accurate.
Q. How are weeks of pregnancy counted?
A. The first day of your last period is counted as week 0, day 0 of pregnancy; actual conception typically occurs about 2 weeks after that date.