Due date guide (EDD): what it means
“EDD” means estimated due date. Most calculators estimate around 40 weeks (280 days) from the first day of your last menstrual period (LMP), then adjust based on cycle length or clinical info.
LMP method (most common)
If you know your LMP, many tools add ~280 days, then adjust for shorter/longer cycles.
Ultrasound dating
Clinicians can estimate gestational age from ultrasound and refine the EDD. Many tools accept ultrasound GA.
IVF / ART
IVF uses embryo transfer date + embryo age to estimate conception and due date.
FAQs
Why do due date tools show a range?
Because the due date is an estimate and many people deliver earlier or later.
What if my cycle is irregular?
If your cycle varies a lot, LMP-based estimates can be less reliable. Ultrasound dating from a clinician may help.
What should I do after I get my EDD?
Use it for planning and tracking—then confirm with your healthcare provider for accurate prenatal care decisions.