Pregnancy Due Date Calculator

Your estimated due date (EDD) is calculated by taking the first day of your last menstrual period (LMP), adding 280 days (40 weeks), and adjusting for your personal cycle length. If your cycle is shorter or longer than the standard 28 days, your due date shifts accordingly.

Only around 4% to 5% of babies arrive on their exact calculated due date. Most babies are born within a 2-week window before or after the due date (between 37 and 42 weeks). The calculator gives you a reliable reference date to track milestones.

If you have irregular periods or cannot remember your LMP date, you can calculate your due date using your conception date, or select the Ultrasound mode if you've already had a dating scan with your doctor.

Yes. Early first-trimester dating ultrasounds measure the fetus's crown-rump length (CRL) and are considered the gold standard for gestational age accuracy. If your ultrasound differs by more than 5-7 days from your LMP calculation, your obstetrician may update your official due date.

Gestational age counts pregnancy duration starting from the first day of your last period (LMP). Fetal age is the actual developmental age of the baby, starting from conception (which typically occurs about 2 weeks after your period).

A full-term pregnancy lasts between 39 weeks 0 days and 40 weeks 6 days. Babies born at 37 to 38 weeks are considered early term, while those born at 41 weeks are late term.

IVF due dates are calculated based on the exact transfer date and age of the embryo. For a Day 3 embryo transfer, 263 days are added to the transfer date. For a Day 5 blastocyst transfer, 261 days are added to the transfer date.

• First Trimester: Weeks 1 through 12 (Organ formation & initial heartbeat).
• Second Trimester: Weeks 13 through 27 (Movement, gender reveal & rapid growth).
• Third Trimester: Weeks 28 through 40+ (Lung maturation & full weight gain).