Pregnancy Week Calculator

Pregnancy Week Calculator

This calculator estimates how many weeks pregnant you are and your expected due date, based on the first day of your last menstrual period. Pregnancy is commonly measured in weeks counted from that date, which is why the figure can be a couple of weeks ahead of the actual conception time. The result is divided into the familiar first, second and third trimesters.

Knowing your current week helps you follow your baby development, anticipate routine check-ups and understand which milestones are typical at each stage. A full-term pregnancy is generally around 40 weeks counted from the last period, though every pregnancy is unique.

How to use it

Enter the first day of your last menstrual period, and the tool calculates your current week and an estimated due date in seconds. The calculation runs privately in your browser, with no data saved on a server.

This is an informational estimate, not a medical diagnosis. Cycle length and individual factors can shift the dates, and an ultrasound dating scan is more precise. Always follow the guidance of your doctor or midwife for monitoring and care throughout your pregnancy.