FAQ: Pregnancy Due Date Calculator
1. How does this calculator work?
It adds 280 days (40 weeks) to your last menstrual period (LMP) or 266 days to your conception date to estimate due date.
2. What's the difference between LMP and conception date methods?
LMP assumes ovulation 14 days after your period starts. Conception date is more precise if you know when you conceived.
3. Is the due date exact?
No, it's an estimate. Only about 5% of babies are born on their due date. Consult your doctor for accurate tracking.
4. What if I don't know my LMP?
Use the conception date if known, or see your healthcare provider for an ultrasound to estimate gestational age.
5. Does this account for irregular cycles?
It's based on a standard 28-day cycle. If your cycles are irregular, results may vary—consult a doctor.
6. Can I use this for twins or multiples?
Due dates for multiples may be earlier. This tool provides a general estimate; your OB-GYN will adjust based on ultrasounds.
7. Is my information private?
Yes, all calculations are done locally in your browser—no data is stored or sent.