Medical & Affiliate Disclosure

Medical Disclaimer

DueDateTool.org provides educational information only and is not a substitute for professional medical advice, diagnosis, or treatment.

The calculators, articles, and resources on this site are for general informational purposes. They should not be used as a replacement for consultation with a qualified healthcare provider, including obstetricians, certified nurse-midwives, reproductive endocrinologists, or family physicians.

Always seek the advice of your healthcare provider with any questions you may have regarding your pregnancy, fertility, or reproductive health. Never disregard professional medical advice or delay seeking it because of something you have read on this website.

Due date calculations are estimates based on mathematical formulas. Only approximately 4-5% of babies are born on their exact estimated due date. Normal full-term delivery occurs between 37 and 42 weeks of gestation. Individual factors such as irregular menstrual cycles, unknown conception dates, multiple pregnancies, and maternal health conditions can affect calculation accuracy.

Early ultrasound dating (8-13 weeks) is the most reliable method for establishing gestational age. Always confirm your due date with your healthcare provider through clinical examination and ultrasound.

About the Author

This site is authored by Sophie Miller, CNM (Certified Nurse-Midwife), licensed in Oregon with additional training in lactation consulting and perinatal mental health.

Sophie has 8+ years of clinical practice experience and currently works at a birth center in Portland, Oregon. She is also a mother of two and is currently pregnant with her second child.

While Sophie is a licensed healthcare professional, use of this website does not create a patient-provider relationship between you and Sophie Miller or DueDateTool.org. Communication through this website does not constitute medical consultation.

Affiliate Disclosure

DueDateTool.org is a free resource supported by advertising and affiliate partnerships. We may earn a commission when you click on links to products or services from our affiliate partners.

This does not affect the price you pay for any products or services. Our editorial content is independent of our affiliate relationships, and we only recommend products or services that we believe will be genuinely helpful to our readers.

We are committed to transparency and will always disclose affiliate relationships when relevant. If you have any questions about our affiliate partnerships, please contact us at contact@duedatetool.org.

Privacy & Data

All calculations on DueDateTool.org happen entirely in your web browser. Your health data — including last period dates, conception dates, IVF transfer dates, and cycle information — is never sent to our servers, never stored in a database, and never shared with third parties.

We use local storage only to optionally remember your calculator inputs if you choose to enable the "Save my inputs" feature. This data stays on your device and can be cleared at any time through your browser settings.