When will your baby arrive?

Pick the method that fits you. Everything is computed on your device: nothing is sent, nothing is stored, and no account is required.

🔒 This runs entirely in your browser. No data is sent to or kept on any server — that is the Mama4care philosophy.

How we calculate (full transparency)

Last period: 280 days after the first day of your last period, adjusted to your cycle length if it isn’t 28 days.
Conception: 266 days after the conception date.
IVF: 263 days after a day-3 transfer, 261 days after a day-5 transfer — the most precise method, since the start date is known exactly.
Ultrasound: the due date is aligned with the gestational age measured by your sonographer — the medical reference in the 1st trimester.

Your questions

Is the calculated date reliable?

It is a solid estimate — but an estimate: only about 4 in 100 babies arrive exactly on their due date, and most arrive between weeks 37 and 42. A first-trimester ultrasound remains the most accurate dating method.

Weeks pregnant vs. gestational weeks?

Gestational age is counted from the first day of your last period; conception happens about 2 weeks later. Health professionals use gestational age — so does this calculator.

What happens after the calculation?

The Mama4care app follows you week by week: baby’s size, tailored tips, nutrition, exercises — then the whole postpartum. Your data stays encrypted on your phone.

Indicative estimate — only your midwife or doctor can precisely date your pregnancy. If in doubt or worried about a symptom, seek professional advice.

Keep going, week after week

Personalised follow-up, a caring assistant day and night, and data that never leaves your phone.

Discover the Mama4care app