Pregnancy Calculator

Calculation Methods

• Last Menstrual Period (LMP): The most common method. Due date is estimated at 280 days (40 weeks) from the first day of your last period, based on Naegele's rule.
• Conception Date: If the date of conception is known, the due date is 266 days (38 weeks) from that date.
• Known Due Date: Enter a due date from your healthcare provider to see week-by-week details and track your current progress.

Understanding Trimesters

• 1st Trimester (Weeks 1-13): Early development period. Morning sickness is common. All major organs begin forming.
• 2nd Trimester (Weeks 14-27): Energy returns and baby movement is felt. Often considered the most comfortable trimester.
• 3rd Trimester (Weeks 28-40): Final growth and preparation for birth. Baby gains weight rapidly.

Week-by-Week Tracking

Baby size comparisons and development milestones are based on averages from medical literature. Actual growth varies between pregnancies.

Weight Gain Guidelines

Recommended weight gain ranges are from the Institute of Medicine (IOM) and depend on pre-pregnancy BMI:

BMI Category	Total Gain (kg)	Total Gain (lbs)
Underweight (<18.5)	12.5 - 18	28 - 40
Normal (18.5 - 24.9)	11.5 - 16	25 - 35
Overweight (25 - 29.9)	7 - 11.5	15 - 25
Obese (≥30)	5 - 9	11 - 20

Important Notes

• This calculator provides estimates. Only about 5% of babies are born on their exact due date.
• Full term is considered 37-42 weeks.
• Due dates can be adjusted based on ultrasound measurements.
• Always consult with your healthcare provider for accurate medical advice.

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