Weeks Pregnant Calculator
First Day of Last Menstrual Period
Pregnancy is counted in weeks from the first day of the Last Menstrual Period (LMP). Full term is 40 weeks. Babies born 37–42 weeks are considered full term.
- 1Weeks = (Today − LMP) / 7
- 2Due date = LMP + 280 days (Naegele's rule)
- 3First trimester: 1–13 weeks; Second: 14–27; Third: 28–40
- 4Preterm: born before 37 weeks
LMP 1 January, checking 1 April=13 weeks pregnant; second trimester begins next week
| Trimester | Weeks | Key events |
|---|---|---|
| First | 1–13 | Organ formation; highest miscarriage risk |
| Second | 14–27 | Anatomy scan; fetal movement |
| Third | 28–40 | Rapid growth; birth preparation |
References
🔒
100% Bezpłatny
Bez rejestracji
✓
Dokładny
Zweryfikowane wzory
⚡
Natychmiastowy
Wyniki od razu
📱
Przyjazny mobilny
Wszystkie urządzenia