The Pregnancy Due Date Calculator estimates your baby’s arrival — the estimated due date (EDD) — and shows how far along you are right now, which trimester you are in, and the key dates along the way.

How the due date is worked out

A full-term pregnancy is counted as 40 weeks (280 days) from the first day of your last menstrual period (LMP). This is known as Naegele’s rule. If you know your conception date instead, the due date is about 266 days later; for IVF, it is counted from the embryo transfer, adjusted for the embryo’s age.

Cycle length matters

The 28-day cycle is just an average. If your cycle is longer or shorter, ovulation shifts, so the calculator adjusts the due date by the difference from 28 days for a more accurate estimate.

Trimesters

Pregnancy is split into three trimesters: the first (weeks 1–13), the second (weeks 14–27), and the third (week 28 to birth). A baby is considered full term from 37 weeks.

This is an estimate only — just about 1 in 20 babies arrive exactly on their due date, and a normal delivery can happen any time from 37 to 42 weeks. Always follow the guidance of your doctor or midwife. Everything runs in your browser and nothing is uploaded.