What percentage of babies are born on their exact due date?

Pregnancy Due Date Calculator - Naegele's Rule & Trimester Timeline

Calculate your estimated delivery date (EDD), current gestational age in weeks and days, and trimester milestones using clinical Naegele's rule.

⚙️ Configuration & Inputs

First Day of Last Menstrual Period (LMP)

Average Menstrual Cycle Length (Days) Standard cycle is 28 days

📊 Results & Analysis

Estimated Due Date (EDD) May 22, 2027 280 Days Total Pregnancy

Current Gestational Age 12 Weeks, 4 Days Based on LMP

Current Trimester First Trimester Week 1 through Week 13

Conception Date (Estimated) August 29, 2026 Ovulation (~14 days after LMP)

Franz Naegele's standard rule: Due Date = First day of LMP + 1 year - 3 months + 7 days.

Only about 4% to 5% of babies arrive on their exact predicted date. Over 80% are born within a 2-week window (between 37 and 42 weeks of gestation).