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Due Date Calculator

Calculate expected due date and pregnancy week from LMP.

28 days

Standard is 28 days. Adjust to your cycle.

About Due Date Calculator

From Last Menstrual Period: Adds 280 days (40 weeks) to the start of your last period. Adjusted if your cycle differs from 28 days.

From Ovulation/Conception Date: Adds 266 days (38 weeks) to the ovulation (conception) date.

Important: This is an estimate only. The accurate due date is determined by your doctor based on ultrasound examination. Always consult your obstetrician.

📖How to Use
  1. 1Enter the first day of your last menstrual period (LMP)
  2. 2Your estimated due date (EDD = LMP + 280 days) is calculated automatically
  3. 3See gestational week and key milestones throughout pregnancy
💡Tips & Knowledge
  • EDD is calculated as LMP + 280 days (40 weeks) using Naegele's rule
  • Full-term is 37 to 41 weeks 6 days. About 90% of births occur in this window
  • This is an estimate only. Please consult an OB-GYN for accurate diagnosis

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All calculations run in your browser. No data is sent to any server.