Pregnancy Due Date Calculator
Estimate your due date and how far along you are, from your last period or conception date.
Estimated due date
You are currently
This calculator provides a general estimate for informational purposes only. It is not a medical device and does not provide medical advice or diagnosis. Always consult a qualified healthcare professional about your individual health circumstances.
Frequently Asked Questions
How is my due date calculated?
Using Naegele's rule: your due date is estimated as 280 days (40 weeks) after the first day of your last period, or 266 days after conception if that date is known.
How accurate is this estimate?
This is a general estimate based on average cycle length. Only around 5% of babies are born exactly on their due date — most arrive within two weeks either side. Research has also found that Naegele's rule tends to run slightly early for first pregnancies specifically, with actual delivery averaging a few days later than the 280-day estimate. Your doctor may adjust your date based on an ultrasound scan, which is generally considered more accurate than this calculation alone.
What if my cycle isn't 28 days?
Naegele's rule assumes a standard 28-day cycle. If your cycles are longer or shorter, your actual due date may vary — this is best confirmed with your healthcare provider.
Want lab-grade insight to go with this estimate?
Family Planning Tests
