Pregnancy Due Date Calculator
Calculate your estimated due date and key pregnancy milestones from your last period.
About Naegele's Rule
Naegele's Rule (1850) calculates estimated due date (EDD) by adding 280 days (40 weeks) to the first day of the last menstrual period, adjusting for cycle length. Actual delivery occurs within ±2 weeks of EDD in ~80% of pregnancies.
Pregnancy Timeline
| Milestone | Week |
|---|---|
| Estimated Conception | ~Week 2 |
| End of 1st Trimester | Week 13 |
| End of 2nd Trimester | Week 26 |
| Full Term | Week 37–40 |
| Estimated Due Date | Week 40 |
This calculator is for educational purposes only. Consult a qualified healthcare professional for medical advice.