Pregnancy Week Calculator by Due Date
Find out which week of pregnancy you're in based on your due date
Your Pregnancy Progress
Upcoming Pregnancy Milestones
About Pregnancy Week Calculation
This calculator helps you determine your current pregnancy week based on your due date. Pregnancy typically lasts about 40 weeks from the first day of your last menstrual period (LMP).
How It Works:
- Enter your estimated due date (provided by your healthcare provider)
- The calculator determines how many weeks pregnant you are
- It shows your progress through the pregnancy timeline
- You'll see important upcoming milestones in your pregnancy journey
Understanding Trimesters:
First Trimester
Weeks 1-12
Early development, morning sickness common
Second Trimester
Weeks 13-26
Reduced nausea, baby movements begin
Third Trimester
Weeks 27-40
Final growth, preparation for birth
Pregnancy Week Calculator - Frequently Asked Questions
How accurate is the pregnancy week calculator?
The calculator provides an estimate based on the standard 40-week pregnancy model. For the most accurate assessment of your pregnancy week, consult with your healthcare provider who can consider ultrasound measurements and other factors.
What if I don't know my exact due date?
If you're unsure of your due date, you can use the date of your last menstrual period (LMP) as a starting point. Typically, due dates are calculated as 40 weeks from the first day of your LMP. However, an ultrasound dating scan provides the most accurate due date estimation.
Why does pregnancy count as 40 weeks when it's 9 months?
Pregnancy is counted from the first day of your last menstrual period, which is typically about two weeks before conception occurs. This accounts for the additional weeks in the 40-week count. Also, months vary in length, while weeks provide a more consistent measurement.