Weeks Pregnant Calculator
How many weeks pregnant are you?
Enter the first day of your last menstrual period to see today's gestational age in weeks and days, your trimester and your estimated due date. You can also open a week page such as ‘12 weeks pregnant’ to see the due date that goes with it. Today is Monday, October 5, 2026.
How weeks are counted
Weeks are counted from the first day of the last period, not from conception. A person who is 12 weeks pregnant conceived about 10 weeks ago.
An estimate, not advice
This tool is date arithmetic only. A healthcare provider sets the official dating and answers medical questions.
Frequently asked questions
How do I calculate how many weeks pregnant I am?
Enter the first day of your last period.
What is the first trimester?
Up to 13 weeks and 6 days.
What is the second trimester?
14 weeks to 27 weeks and 6 days.
What is the third trimester?
From 28 weeks.
What is full term?
39 weeks to 40 weeks and 6 days.
Is it counted from conception?
No, from the last period.
How long is a pregnancy?
About 40 weeks.
Is this medical advice?
No.