Pregnancy Date Planning Calculator
Estimate a due date from last period timing and cycle length for early pregnancy planning.
Tool-specific inputs
These inputs aren't part of the dashboard. Adjust them to refine the result above.
How this works
Uses Naegele's rule: last menstrual period plus 280 days, adjusted for cycle length compared with 28 days.
Medical disclaimer
Educational tool only — not medical advice. Consult a qualified provider.
Goal notes
Use this pregnancy date planning page for a broad calendar estimate, not for confirming pregnancy dating or medical timing. The calculator opens with a recent last-period date and a twenty-eight-day cycle so the result follows a common due-date estimate method. Real pregnancy dating can change after clinical evaluation, cycle irregularity, ovulation timing, assisted reproduction, or ultrasound findings. Update the dates to match your history and use the result as a conversation aid with a qualified pregnancy care provider, especially if your cycles are irregular, symptoms are concerning, or you need medication guidance.
- Selected goal
- Plan pregnancy dates
- Starting cycle length
- 28 days
- Planning note
- A clinician can confirm or revise dating based on individual history and examination.
- Primary calculator
- Due Date Calculator
Source: CDC General Pregnancy Planning Information (accessed 2026-05-06).
Frequently asked questions
Is this pregnancy date estimate official?+
No. It is an educational estimate from the dates entered. A pregnancy care provider can confirm dating and explain any changes.
Why can cycle length change the result?+
The calculator adjusts the estimate when cycle length differs from 28 days because ovulation timing may differ from the common assumption.
When should I talk with a provider?+
Contact a qualified pregnancy care provider for confirmation, symptoms, medication questions, irregular cycles, or any medical concerns.