Using the Pregnancy Calculator responsibly
Page-specific guidance based on this calculator’s implemented method, inputs, and known limits.
What this result is useful for
Pregnancy dating estimates a due date and related milestones from the information selected: last menstrual period, conception date, ultrasound dating, IVF transfer, or an existing due date. These methods can produce different estimates because they use different evidence.
Assumptions and limits
Last-period dating assumes a typical relationship between cycle timing and ovulation, with the entered cycle adjustment. Conception may be uncertain, and clinical ultrasound interpretation depends on gestational age and measurement. The result is not a confirmation of pregnancy or fetal wellbeing.
How to check the result
Check every calendar date and the direction of any cycle adjustment. Prenatal records should use the due date established by the treating clinician, especially after ultrasound or assisted reproduction. Contact a qualified professional for symptoms, medication questions, or urgent concerns.