Due Date Calculator: Pregnancy EDD & Week-by-Week Milestones

Pregnancy Due Date Calculator

Calculate your estimated delivery date (EDD) and track baby developmental milestones with our free Pregnancy Due Date Calculator. Select your dating method—Last Menstrual Period (LMP), conception date, IVF/FET transfer, or ultrasound scan—to generate an accurate timeline.

Pregnancy Due Date & Milestones

Choose your known dating method below to calculate your estimated delivery date (EDD) and track key developmental milestones.

Calculation Method

First Day of Last Period *

Average Cycle Length (Days)

Standard clinical baseline is 28 days.

First Trimester

Estimated Due Date (EDD)

You are currently -- pregnant (-- days to go).

Pregnancy Progress (40 Weeks) 0% Complete

1st Trimester (Weeks 1–13)

2nd Trimester (Weeks 14–27)

3rd Trimester (Weeks 28–40+)

Gestational Age

0w 0d

Completed pregnancy time

Estimated Conception

Likely fertilization window

Fetal Development

Typical size & milestones

Key Pregnancy Milestones Schedule

Chronological developmental milestones and clinical checkups based on your EDD:

Gestation	Milestone Event	Significance	Projected Date

Clinical Reference Note: Estimated Due Date (EDD) calculations represent a projection based on 280 days (40 gestational weeks). Only roughly 4% to 5% of babies are born on their exact due date; most healthy full-term deliveries occur within a window spanning 37 to 42 weeks. Always confirm your clinical dating with your obstetrician or midwife.

How Pregnancy Due Dates are Calculated

A full-term human pregnancy averages 280 days (40 weeks) from the first day of the last menstrual period (LMP), or 266 days (38 weeks) from actual fertilization. Common clinical methodologies include:

Naegele’s Rule (LMP): Calculates due date by taking the first day of the last menstrual period, adding 280 days, and adjusting for personal cycle length variations away from the standard 28-day cycle.
Conception / Ovulation Date: Ideal for individuals tracking luteinizing hormone (LH) surges or basal body temperature; gestation is determined by adding 266 days directly to the conception date.
IVF / FET Transfer: In-vitro fertilization dating accounts for the precise developmental age of the transferred embryo (Day-3 or Day-5 blastocyst) plus remaining gestation time.
Ultrasound Crown-Rump Length (CRL): In the first trimester, high-resolution ultrasound measurements of embryo length provide the gold standard for clinical dating accuracy (+/- 3 to 5 days).