SSW Calculator – Calculate Week of Pregnancy & Due Date

Sirawan Sindi

May 17, 2026

Schwangere Frau sitzt im hellen Babyzimmer und hält liebevoll ein Ultraschallbild vor ihren Babybauch

Pregnancy Week Calculator – Calculate your pregnancy week & due date

Easily calculate your current week of pregnancy, your estimated due date, and important milestones of your pregnancy.

First day of your last period

Note: The calculation is based on the standard 40-week method starting from the first day of your last period.

Your result 🧡

🍼 Current pregnancy week

📅 Estimated due date

🤰 Month of pregnancy

🛡️ Start of maternity leave

✨ Your baby's zodiac sign

🧡 Matching BabyLions® tip

How does the pregnancy week calculator work?

The pregnancy week calculator determines your week of pregnancy based on the first day of your last period. This method is commonly used to estimate the expected due date.

Important milestones of your pregnancy

✔ Calculate current pregnancy week
✔ Find out your estimated due date
✔ Estimate your month of pregnancy
✔ Calculate the start of maternity leave
✔ Discover relevant BabyLions® guides

Helpful guides for expectant parents

Hospital bag checklist Baby essentials: The ultimate checklist Packing your diaper bag: The perfect checklist Baby development in the first year How much sleep does my baby need?

Frequently asked questions about the pregnancy week calculator

How accurate is a pregnancy week calculator?

The calculator offers a good orientation. However, the actual due date may vary, as every baby develops individually.

When does pregnancy count from?

Medically, pregnancy is calculated from the first day of your last period.

When does maternity leave start?

In Germany, maternity leave typically begins 6 weeks before the estimated due date.

What does "SSW" mean?

SSW stands for "Schwangerschaftswoche" (pregnancy week). This value shows how far your pregnancy has mathematically progressed.

Can the due date be changed later?

Yes, your doctor may adjust your estimated due date, especially after ultrasound examinations.

Important note: This calculator is for informational purposes only and does not replace medical advice. If you have questions about your pregnancy, please consult your doctor or midwife.