Calculate your estimated due date from LMP or conception date.
Once you know you're pregnant, the due date question comes almost immediately — and this calculator gives you an estimate along with your current week, trimester, and key milestone dates. It uses the standard obstetric method: 280 days (40 weeks) from the first day of your last menstrual period.
Your care provider will confirm your due date with an early ultrasound, which is more accurate than any date-based calculation, particularly if your cycles aren't a regular 28 days. The calculated date is a useful planning anchor until that confirmation.
Due dates are always estimates — statistically, the majority of first-time mothers deliver between 39 and 41 weeks. The date itself is the midpoint of a natural range, not a hard deadline.
Reasonably accurate for people with regular 28-day cycles, but less so if cycles vary. An early ultrasound (before 14 weeks) is the most reliable dating method and will be used by your midwife or OB as the reference date.
Your care provider will typically use the ultrasound date, particularly if the difference is more than 7-10 days. This is normal and doesn't mean anything is wrong — it usually just reflects a slightly different ovulation timing than average.
Sex can typically be determined at the 20-week morphology ultrasound, or earlier with non-invasive prenatal testing (NIPT) if offered. Some parents prefer to wait until birth — this calculator can't tell you either way.
EDD (Estimated Due Date) and EDC (Estimated Date of Confinement) mean the same thing — the estimated date your baby will be born. EDC is older terminology that's largely been replaced by EDD in modern use.