ToolAtlasNaegele’s rule from last menstrual period or a conception date you type. It is a calendar estimate. Clinical dating, especially ultrasound, can disagree — and that clinical date is the one that matters.
You know an LMP (or a conception date) and want the classroom due-date math. That is this page. Ultrasound and your midwife or OB still own the real date.
Not date difference as a pregnancy product. Not age calculator.
What the form does
Applies Naegele-style arithmetic from the date you enter. Cycle length is an assumption, not a lab result.
Honest limits
- Not a confirmation of pregnancy.
- Not IVF protocol math unless you type the date they gave you.
- Not a birth-plan or symptom checker.
If dates are sensitive, keep them off random cloud “pregnancy apps.” This tab does not upload them — and still is not care.