Pregnancy Week Calculator
Find out exactly how many weeks pregnant you are and discover your current trimester and baby's development stage.
How Many Weeks Pregnant Am I?
Enter the first day of your last menstrual period to calculate your current pregnancy week
Select the first day of your last menstrual period to calculate how many weeks pregnant you are.
Key Features
Pregnancy Trimesters
0-12 weeks • Organ development • Morning sickness common
13-27 weeks • "Golden period" • Baby movement felt
28+ weeks • Rapid growth • Preparation for birth
Key Weekly Milestones
How to Use the Pregnancy Week Calculator
Step-by-Step Instructions
Enter Last Menstrual Period
Input the first day of your last menstrual period using the date picker.
Calculate Current Week
Get your exact gestational age in weeks and days based on standard pregnancy dating.
Review Pregnancy Progress
See your trimester status and overall pregnancy progress as a percentage.
Explore Weekly Development
Learn about baby's size, development milestones, and what to expect each week.
Track Important Milestones
Monitor key pregnancy milestones and developmental benchmarks by week.
Plan Prenatal Visits
Use week-by-week information to schedule appropriate prenatal care and tests.
Pro Tips for Week Tracking
Weekly progression: Pregnancy weeks start from the first day of LMP, not from conception date.
Trimester transitions: 1st trimester: 1-12 weeks, 2nd: 13-27 weeks, 3rd: 28-40 weeks.
Development tracking: Each week brings significant changes - follow baby's growth and development.
Appointment timing: Use gestational age to schedule appropriate prenatal tests and screenings.
Medical accuracy: Healthcare providers may adjust dating based on ultrasound measurements.
Frequently Asked Questions
How many weeks pregnant am I?
To calculate how many weeks pregnant you are, count the days from the first day of your last menstrual period (LMP) to today, then divide by 7. Our calculator does this automatically for accurate results. For a comprehensive guide covering 5 different methods to determine pregnancy weeks, see our detailed article: How to Know How Many Weeks Pregnant You Are.
How do you calculate pregnancy weeks?
Pregnancy weeks are calculated from the first day of your last menstrual period (LMP), not from conception. Count the total days since LMP and divide by 7 to get weeks and remaining days.
How many weeks is each trimester?
First trimester: 0-12 weeks, Second trimester: 13-27 weeks, Third trimester: 28-40+ weeks. Each trimester represents different stages of pregnancy and baby development.
What trimester am I in?
Your trimester depends on your pregnancy week: 1st trimester (0-12 weeks), 2nd trimester (13-27 weeks), or 3rd trimester (28+ weeks). Our calculator shows your current trimester automatically.
How accurate is the pregnancy week calculator?
The pregnancy week calculator is very accurate when based on a known last menstrual period date. It uses the standard medical calculation method used by healthcare providers worldwide.
When does each trimester start and end?
1st trimester: Week 1-12, 2nd trimester: Week 13-27, 3rd trimester: Week 28-40+. These divisions help track different phases of pregnancy development and care.
Important Medical Disclaimer
This pregnancy week calculator provides estimates only and should not replace professional medical advice.Pregnancy dating can vary based on individual factors and cycle irregularities. Always consult your healthcare provider for accurate pregnancy dating, monitoring, and medical advice throughout your pregnancy journey.
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