Health & Family
Pregnancy Due Date Calculator
Free pregnancy due date calculator. Estimate your baby’s arrival based on last menstrual period, conception date, or ultrasound.
Calculation Method
Most women have a 28-day cycle.
How is the Due Date Calculated?
By default, healthcare providers use Naegele's rule to calculate your estimated due date (EDD). This method involves adding 280 days (40 weeks) to the first day of your last menstrual period (LMP). Our calculator also allows you to adjust the calculation if your average cycle length is shorter or longer than the standard 28 days.
If you know the exact date of conception (for example, through IVF), you can select the "Conception Date" method. This adds exactly 266 days (38 weeks) to your conception date to find your EDD.
How Accurate Is the Due Date?
An estimated due date (EDD) is just that — an estimate. Only about 4–5% of babies are born on their exact due date. Most pregnancies last between 37 and 42 weeks, and any birth in that window is considered full-term.
Your healthcare provider may adjust the due date after the first ultrasound if the measurements differ significantly from the LMP-based calculation.