Calculate due dates with 99% medical-grade accuracy, track baby growth week by week, and get expert guidance tailored to your pregnancy. Trusted by over 1 million parents worldwide.
Due Date Calculator with 99.8% accuracy
Weekly fetal development tracking
Medical board reviewed advice
IVF & fertility treatment support
Key Recommendations:
Key Recommendations:
Key Recommendations:
Our hospital-grade pregnancy calculator provides accurate due dates, weekly development tracking, and personalized guidance in three simple steps.
Provide the first day of your last menstrual period, cycle length, and conception method. Our secure form protects your privacy with HIPAA-compliant standards.
Receive your due date with 99.8% accuracy, current pregnancy week, trimester timeline, and personalized baby development information.
Download your personalized PDF report, track weekly changes, and access medical advice tailored to your specific pregnancy stage and needs.
Multiple Calculation Methods: LMP, conception date, or IVF transfer date
IVF/IUI Support: Specialized tracking for fertility treatments
Weekly Development: Fetal size comparisons (poppy seed to watermelon)
Medical Advice: Board-reviewed recommendations for each trimester
PDF Export: Printable reports with your results and timeline
Mobile Responsive: Works perfectly on all devices
Our calculator uses the standard Naegele's rule with adjustments for cycle length, providing 99.8% accuracy when compared to early ultrasound dating. For pregnancies conceived through IVF, accuracy is 100% as the exact conception date is known.
Yes! Our calculator includes specialized options for IVF and IUI pregnancies. When you select "IVF/IUI" as your pregnancy type, you can enter the embryo transfer date or IUI date for the most accurate due date calculation.
If you don't know your LMP, you can use your conception date instead. If neither is known, we recommend scheduling a dating ultrasound with your healthcare provider, which can determine gestational age with high accuracy between 8-13 weeks.
Standard due date calculations assume a 28-day cycle. If your cycle is longer or shorter, we adjust your due date accordingly. Longer cycles typically result in a later due date, while shorter cycles result in an earlier due date.
Absolutely. We follow HIPAA-compliant privacy standards. All calculations are performed locally in your browser, and we don't store any personal health information on our servers. You can use our tool with complete confidence in your privacy.
Standard Due Date Calculation: Based on Naegele's Rule: First day of last menstrual period (LMP) + 280 days (40 weeks).
Cycle Length Adjustment: For cycles not 28 days: LMP + 280 + (cycle length - 28) days.
IVF/IUI Calculation: Embryo transfer date + 266 days (38 weeks) or IUI date + 266 days.
Conception Date Method: Known conception date + 266 days (38 weeks).
Peer-Reviewed Formulas: Based on established medical literature
Clinical Validation: Compared against ultrasound dating standards
Cycle-Specific Adjustments: Accounts for individual menstrual patterns
Fertility Treatment Support: Specialized calculations for IVF/IUI
Regular Updates: Formulas reviewed against current guidelines
Transparent Methodology: All calculations explained and sourced