What is Pregnancy Due Date Calculator?
The Pregnancy Due Date Calculator is a trusted health tool that estimates your baby's delivery date, current gestational age, and trimester progress. By inputting the first day of your Last Menstrual Period (LMP) or Conception Date, the tool calculates dates using Naegele's rule, helping parents-to-be track fetal development weeks and prepare for their new arrival.
Formula
Due Date (LMP Method) = First Day of LMP + 280 Days (40 Weeks)
Benefits of Using Pregnancy Due Date Calculator
Track Growth Weeks - Monitor your progress week-by-week and trimester-by-trimester.
Accurate Due Date - Calculates delivery dates based on standardized clinical rules.
Plan Appointments - Helps anticipate doctor visits, prenatal scans, and birth planning.
Developmental Milestone Guidance - Pinpoints estimated conception and milestone periods.
Pro Tip: Only about 4% of babies are born on their exact due date. Consider the due date as a helpful center point for a 4-week window (from week 37 to 42) when delivery is highly likely.
Frequently Asked Questions
It is a standard method of calculating the due date. It subtracts three months and adds seven days (plus one year) to the first day of the last menstrual period.
Calculators provide an estimate based on a standard 28-day menstrual cycle. Ultrasounds in the first trimester are the most accurate way to establish a pregnancy timeline.
If your cycles are shorter or longer than 28 days, a calculation based on an early ultrasound date will be much more reliable than LMP calculations.
First Trimester (weeks 1 to 12), Second Trimester (weeks 13 to 26), and Third Trimester (weeks 27 to birth).
Conception typically happens about 2 weeks after the start of LMP. Clinical gestation is counted from LMP, meaning you are considered 2 weeks pregnant at conception.
Reviewed by Rahul Kumar | Founder, WPFixHub
Updated: August 2026