Due Date Calculator
Calculate your baby's due date based on your last menstrual period (LMP) or conception date. This calculator helps expectant mothers estimate when their baby will arrive and plan for pregnancy milestones.
Calculate Due Date
Results
Enter a date above to calculate your due date
How to Use This Calculator
To calculate your due date, choose your preferred method and enter the corresponding date. The Last Menstrual Period (LMP) method is most commonly used and requires the first day of your last period. If you know your conception date, you can use that method for potentially more accurate results.
How It Works
The due date calculator uses Naegele's Rule, which adds 280 days (40 weeks) to the first day of your last menstrual period. This method assumes a 28-day menstrual cycle with ovulation occurring on day 14.
LMP Method: Due Date = LMP + 280 days + (Cycle Length - 28 days)
Conception Method: Due Date = Conception Date + 266 days
Example Calculation
If your last menstrual period started on January 1, 2024, and you have a 28-day cycle:
Due Date = January 1, 2024 + 280 days = October 7, 2024
Frequently Asked Questions
How accurate is the due date calculator?
Due date calculators provide an estimate. Only about 5% of babies are born on their exact due date. Most babies are born within two weeks before or after the estimated due date.
What if I have irregular periods?
If you have irregular periods, the conception date method may be more accurate, or consult with your healthcare provider for an ultrasound-based due date.
When should I see a doctor?
Schedule your first prenatal appointment as soon as you confirm your pregnancy, ideally between 6-8 weeks after your last menstrual period.
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