Pregnancy Due Date Calculator

Last Menstrual Period

How It Works

  • LMP: Uses Naegele's Rule (LMP + 280 days). Cycle length adjusts ovulation.
  • Conception: Due date = conception + 266 days.
  • Ultrasound: Derives LMP from ultrasound date and GA, then calculates EDD.
  • IVF: Adjusts embryo age to conception equivalent, then calculates EDD.