Pregnancy Due Date Calculator
Estimate your baby’s arrival date accurately. Calculate your estimated due date (EDD), current gestational age, and key pregnancy milestones.
Calculate Your Estimated Due Date
Enter the first day of your last menstrual period or your conception date to see a realistic timeline of your pregnancy journey.
Pregnancy Details
Enter your dates to generate your timeline
Pregnancy Timeline
Your estimated milestones and current progress
Key Pregnancy Milestones
Standard medical milestones based on a typical 40-week pregnancy timeline.
| Milestone | Gestational Age | Significance |
|---|---|---|
| Conception (Estimated) | Week 2 | Ovulation and fertilisation typically occur. |
| First Trimester Ends | Week 13 + 6 days | Major organs formed; miscarriage risk drops significantly. |
| Anatomy Scan Window | Week 18 – 22 | Detailed ultrasound to check baby’s development and sex. |
| Second Trimester Ends | Week 27 + 6 days | Baby reaches viability threshold outside the womb. |
| Full Term Begins | Week 39 | Baby’s lungs and brain are fully developed for birth. |
| Estimated Due Date (EDD) | Week 40 | The calculated target date for delivery. |
Pregnancy Dating FAQ
Everything you need to know about how your due date is calculated and what it means.
The most common method is Naegele’s Rule, which adds 280 days (40 weeks) to the first day of your last menstrual period (LMP), adjusting for your average cycle length. If you know your conception date, 266 days (38 weeks) are added instead.
A due date calculator provides a highly accurate estimate, but only about 4% of babies are born on their exact due date. It is best used as a 2-week window (38 to 42 weeks) for planning, with early ultrasound dating being the most precise medical method.
If your cycles are irregular, the LMP method may be less accurate. In this case, using the conception date (if known) or relying on the dating scan (ultrasound) performed between 8 and 14 weeks of pregnancy will provide a much more reliable estimated due date.
The first trimester ends at 13 weeks and 6 days. The second trimester ends at 27 weeks and 6 days. The third trimester begins at 28 weeks and continues until delivery, typically around 40 weeks.