Calculator Baby Weeks

Track your pregnancy progress with our baby weeks calculator. Calculate your due date, conception date, and understand fetal development stages by week.

How to Use This Calculator

Our baby weeks calculator helps you track your pregnancy timeline. You can calculate:

Your due date from your last menstrual period (LMP)
Your conception date from your due date
Your current pregnancy week based on today's date

Simply enter your last menstrual period date or due date in the calculator, and it will show you the complete pregnancy timeline.

Understanding Pregnancy Weeks

A typical pregnancy lasts about 40 weeks (280 days) from the first day of your last menstrual period to the expected delivery date. This period is divided into three trimesters:

First trimester: Weeks 1-12
Second trimester: Weeks 13-28
Third trimester: Weeks 29-40

Note: Some healthcare providers count weeks differently, starting from the first day of the last menstrual period or from the first day of the menstrual period before conception.

Fetal Development by Week

Fetal development progresses rapidly during pregnancy. Here are some key milestones:

Key Development Stages

Weeks 1-4: Fertilization, implantation, and early organ formation
Weeks 5-8: Major organs begin to form, heart starts beating
Weeks 9-12: Limbs develop, face becomes recognizable
Weeks 13-16: Baby can hear sounds, fingers and toes form
Weeks 17-20: Baby can make facial expressions, hair grows
Weeks 21-24: Baby can suck thumb, eyelids open
Weeks 25-28: Baby can taste, practice breathing movements
Weeks 29-32: Baby gains weight rapidly, moves frequently
Weeks 33-36: Baby is in "breech" position, practicing breathing
Weeks 37-40: Baby is fully developed, ready for birth

Each week brings new developments, and your healthcare provider can provide more specific information about your baby's growth.

Common Questions About Baby Weeks

FAQ

How accurate is the baby weeks calculator?: The calculator provides an estimate based on standard pregnancy lengths. Individual pregnancies may vary.
Can I use this calculator if I'm pregnant?: Yes, this calculator can help you track your pregnancy timeline and understand fetal development.
What if I don't know my due date?: You can calculate your due date by entering your last menstrual period date in the calculator.
How does the calculator determine conception date?: The calculator subtracts 14 days from your last menstrual period date to estimate conception.
Can I track my pregnancy week by week?: Yes, the calculator shows your current pregnancy week based on today's date.