Conception Date Calculator
Estimate your conception date from your due date or from your Last Menstrual Period.
How to Use the Conception Date Calculator
Estimate your conception date from your due date or from your Last Menstrual Period. Enter your information in the form above and get instant results.
Medical Disclaimer: This tool is for informational purposes only. Always consult your healthcare provider for medical advice.
Frequently Asked Questions
How is conception date estimated?
From a due date, we subtract 266 days (38 weeks). From LMP, we add 14 days (average ovulation day in a 28-day cycle).
Is the conception date exact?
No. Conception date is an estimate based on average cycle length and ovulation timing. Sperm can survive up to 5 days inside the fallopian tubes.
Can I use this to determine paternity?
This calculator provides an estimate only and should not be used for medical or legal decisions. Consult a healthcare provider.