Pregnancy Weeks Calculator
Calculate Your Pregnancy Weeks
Pregnancy Weeks Calculator
Understanding Pregnancy Weeks
Pregnancy weeks are calculated from the first day of your last menstrual period (LMP), not from the date of conception. This method, called gestational age, is the standard used by healthcare providers worldwide.
Knowing your exact pregnancy week helps track fetal development, schedule important prenatal appointments, and prepare for your baby's arrival.
How Pregnancy Weeks Are Calculated
The most common method uses your last menstrual period (LMP) date. Healthcare providers add 280 days (40 weeks) to your LMP to estimate your due date.
Calculation Formula
Gestational Age = (Today's Date - LMP Date) ÷ 7
This gives you the number of completed weeks since your last menstrual period.
Pregnancy Trimesters
First Trimester
Weeks 1-12
- • Major organ formation begins
- • Heart starts beating around week 6
- • Morning sickness may occur
Second Trimester
Weeks 13-26
- • Baby's movements become noticeable
- • Gender can be determined
- • Energy levels often improve
Third Trimester
Weeks 27-40+
- • Rapid weight gain and growth
- • Lungs mature for breathing
- • Baby prepares for birth
Important Pregnancy Milestones
Week 4: Implantation
The fertilized egg implants in the uterine wall, and pregnancy hormones begin to rise.
Week 8: Embryonic Period Ends
All major organs have formed, and the embryo is now called a fetus.
Week 12: End of First Trimester
Risk of miscarriage decreases significantly, and many choose to announce their pregnancy.
Week 20: Anatomy Scan
Detailed ultrasound to check baby's development and potentially determine gender.
Week 28: Third Trimester Begins
Baby's survival rate increases significantly if born prematurely.
Week 36: Term Pregnancy
Baby is considered full-term and ready for birth any time after this point.
Important Notes
This calculator provides estimates based on standard pregnancy calculations.
Always consult with your healthcare provider for accurate dating and medical advice.
Every pregnancy is unique, and actual due dates may vary from calculations.
Comments