Calculate the week of pregnancy (SSW)

The duration of pregnancy and the expected date of birth are important pieces of information for expectant mothers. They help to track the baby's development and prepare for the birth. With our online calculator, you can calculate both the current week of pregnancy and the expected date of birth based on the date of your last period and the length of your menstrual cycle.

Basics of the calculation:

The average length of pregnancy is 40 weeks or 280 days from the first day of your last period. This is based on an average menstrual cycle of 28 days. However, if your cycle is longer or shorter, this will affect the expected date of birth.

How it works

1. Date of last period: Enter the exact date of the first day of your last menstrual period.
2. Length of menstrual cycle: The length of the cycle varies from woman to woman. An average cycle lasts 28 days, but can vary from 21 to 35 days or longer. Enter the usual length of your cycle.

Based on this information, our system will calculate

• Your current week of pregnancy.
• The expected date of birth.

Important notes

• The calculated due date is an approximate estimate. Only about 4% of babies are actually born on their calculated due date.
• The actual length of pregnancy can vary depending on many factors, including the mother's health, lifestyle and genetic factors.
• It is always advisable to discuss all calculations and due dates with your doctor or midwife.

Conclusion

Our online pregnancy weeks and due date calculator offers you a quick and easy way to work out these important dates. It is a useful tool to guide you on your journey to motherhood. However, remember to seek regular medical advice and follow the development of your pregnancy closely. Our website does not provide medical advice. All information is therefore without guarantee.