How the due date is estimated

Naegele's rule: due date = LMP + 280 days. We adjust by (cycle length − 28) days for non-28-day cycles. This is an estimate — most births happen within ±2 weeks of the EDD.

Frequently Asked Questions

Is the Pregnancy Due Date Calculator free to use?

Yes, the Pregnancy Due Date Calculator is 100% free to use. There are no subscriptions, no sign-ups, and no hidden fees.

Is my data safe when using the Pregnancy Due Date Calculator?

Absolutely. All calculations performed by the Pregnancy Due Date Calculator happen locally in your web browser. We do not store, track, or transmit your inputs or results to any server.

How accurate is the Pregnancy Due Date Calculator?

Our Pregnancy Due Date Calculator uses industry-standard formulas and methodology. You can view the exact formula and calculation logic used in the methodology section above to verify the math yourself.

Can I use the Pregnancy Due Date Calculator on my mobile phone?

Yes! The Pregnancy Due Date Calculator is fully responsive and works seamlessly on all devices including smartphones, tablets, and desktop computers.