Health & Fitness
Estimate your due date from LMP, conception, IVF or ultrasound, with weekly milestones and baby size.
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Choose how you want to calculate: last period (LMP), conception date, IVF transfer, or ultrasound.
Enter the relevant date. For LMP, also set your average cycle length; for IVF, pick day-3 or day-5 transfer; for ultrasound, enter the gestational age measured.
Read your estimated due date, current week and day, trimester, and countdown in the results panel.
Explore your milestone timeline, key dates and this week's baby size. Copy or print the summary to share with your partner or keep for appointments.
From the moment two lines appear, the first question is almost always "when is the baby due?" This calculator answers it four different ways — from your last menstrual period, a known conception date, an IVF embryo transfer, or an ultrasound measurement — and then does far more than hand you a single date. It tells you how many weeks and days along you are right now, which trimester you're in, how many days remain, and what's happening at this stage of your pregnancy.
The standard method uses Naegele's rule: a pregnancy is dated as 280 days (40 weeks) from the first day of your last period, and this tool refines that by adjusting for your cycle length, since a longer or shorter cycle shifts ovulation and therefore the due date. If you conceived through IVF, it uses the precise embryo age — a day-5 blastocyst and a day-3 transfer have different, exact timelines — which is why IVF due dates are among the most accurate of all. The ultrasound option lets you enter the gestational age a sonographer measured, the dating method doctors ultimately rely on.
Beyond the date, you get a living picture of the pregnancy: a week-by-week size comparison (from poppy seed to small pumpkin), a milestone timeline covering the heartbeat, the anatomy scan, the viability point and full term, a personalised table of your key dates, and a progress bar with a countdown. It's built to be the page you return to each week. One honest reminder throughout: a due date is an estimate — only about 1 in 20 babies actually arrives on it, and most healthy births happen anywhere in the two weeks either side. Your doctor's dating scan always takes precedence.
Estimating your due date early in pregnancy before your first dating scan.
Working out exactly how many weeks and days pregnant you are today.
Calculating an accurate due date after IVF using the embryo transfer day.
Planning ahead for the anatomy scan, glucose test, maternity leave and key milestones.
If your cycles aren't 28 days, set your real cycle length — it can move the due date by several days and improves the estimate.
IVF and early-ultrasound due dates are more accurate than LMP dating, so trust those if you have them.
Your doctor may adjust your due date after the first-trimester dating scan; that measured date should replace any online estimate.
Note the anatomy-scan window (18–22 weeks) and viability (24 weeks) from your key-dates table so nothing sneaks up on you.
Treating the due date as a deadline. A normal, healthy birth can happen any time from 37 to 42 weeks — the due date is the midpoint, not a guarantee.
Counting pregnancy from conception. Clinically, pregnancy is dated from the last period, so you're already considered ~2 weeks pregnant at conception and 4 weeks at your first missed period.
Using LMP dating with very irregular cycles, where ovulation timing is unpredictable — an ultrasound date is far more reliable in that case.
Calculate your Body Mass Index and see the WHO category.
Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation.
Estimate your daily water intake based on body weight and activity.
Calculate your daily calorie needs (TDEE) for maintenance, cut or bulk.