🤰 Pregnancy Calculator
Estimate your due date, weeks of pregnancy and current trimester from the first day of your last period.
⚠️ Guidance tool only — it does not replace medical advice. The due date is an estimate: only about 5% of babies are born on that exact date. Always consult your doctor.
Frequently asked questions
How is the due date calculated?
With Naegele’s rule: 280 days (40 weeks) are added to the first day of your last period. It is an estimate based on regular 28-day cycles.
How accurate is the due date?
It is a guide: only about 5% of babies are born on the estimated date. Being born between weeks 37 and 42 is normal.
What are the trimesters of pregnancy?
First trimester: weeks 1–13; second: weeks 14–27; third: weeks 28–40. Each stage has its recommended checkups.