🤰 Due Date Calculator

Estimate pregnancy due date.

How to Use the Pregnancy Due Date Calculator

Estimate baby's due date:

  1. Last Period: First day of last menstrual period (LMP).
  2. Cycle Length: Typical length (28 days average, 20-45 normal).

How It Works: Uses Naegele's Rule: 280 days (40 weeks) from LMP, adjusted for cycle length. Assumes ovulation ~day 14.

Notes: Only 5% born on exact due date. Most arrive 37-42 weeks. Early ultrasound more accurate. Consult provider for official date.