Weeks 1 to 13
First
Nausea, secrecy and a lot of waiting. The only purchases that matter are a prenatal vitamin and, if you want it, the NT scan booked inside its eight day window.
Free tools · No account · Nothing to install
One date decides everything else
Enter the first day of your last period and this site stops being generic. Your week. Your scans. The thing you have not bought yet.
Works from LMP, conception, IVF or a scan Nothing is sent anywhere
280 days
The whole thing,
on one line
Forty weeks is not a countdown, it is a sequence of about twenty appointments, deadlines and windows, most of which only work if you hit them. The nuchal scan is valid for eight days. The strep swab has a two week window. Once the site knows your date it knows all of them.
Enter a date above and your position appears on the arc.
Six tools
All free,
all correct
Every one of them takes your date and answers for your week, not in general. No signup wall, no results held back.
01
The one that starts it
Due date calculator
Works from your last period, a known conception date, an IVF transfer or a dating scan. Returns your due date and the 23 dates that hang off it.
02 42 pagesWeek by week tracker
What is developing, what you are likely to feel, and the two or three things worth doing. Opens on your week automatically.
03 For fun, and done properlyChinese gender predictor
The Qing dynasty chart, with a real lunisolar conversion behind it. Most versions online feed it Gregorian dates, which is wrong for six weeks of every year.
04 PrintableHospital bag checklist
Built for the week you are in, so it tells you whether you are early, on time or already late. Ticks are remembered. Prints on two pages.
05 For 3amContraction timer
One big button. Times length and spacing, averages the last five, and tells you plainly when you have hit 5-1-1.
06 52 items, sorted by whenWhat to buy, by week
Not the best strollers of the year. The things you need before week 30, the things that can wait, and the ones people forget until it is too late.
Why the date
A list of
best strollers
helps nobody
A due date is not a fact about October. It is a fact about right now: it says exactly which week you are in, and every useful answer in pregnancy is a function of that week.
At 19 weeks the thing that matters is booking the anatomy scan. At 24 it is the glucose test and buying a car seat, because you cannot leave the hospital without one. At 36 it is the strep swab and having the bag by the door. None of that is useful a month early and all of it is a problem a week late.
So this site asks for one date and then never asks you anything again. The checklist knows. The gear list knows. The week page opens where you are.
Stored in your browser only
No account
Clear it any time
Three acts
Different questions at different ends
Weeks 14 to 27
Second
The easy stretch, and the one to spend. Anatomy scan, glucose screen, car seat, stroller, crib. Everything with a delivery time gets ordered here.
Weeks 28 to 42
Third
Tdap, strep swab, kick counting and the bag by the door from week 35. Buy your own postpartum supplies. Nobody puts them on a registry and everybody needs them.
One email a week
The right week, on the week it matters
What is happening, what to book, what to order. Timed to your date, not to a generic schedule. One click to stop.
Questions
The ones people actually ask
How is a due date calculated?
280 days from the first day of your last period, which is 40 weeks. If your cycle runs longer or shorter than 28 days, ovulation moves and the due date moves with it, which is why this calculator asks. If you know the date of conception the count is 266 days from there instead. IVF is more precise again: a day 5 blastocyst transfer is due 261 days after transfer.
How accurate is it?
About 4 babies in 100 arrive on the due date itself, and roughly 80 percent arrive within two weeks either side. A first trimester dating ultrasound is more accurate than a date worked out from your last period, and where the two disagree your practice will use the scan. That is why there is a scan mode in the calculator.
Why does the count start before I was pregnant?
Because the first day of your last period is the one date most people can name with confidence, and ovulation is not. It means the first two weeks of a 40 week pregnancy happen before there is anything to be pregnant with. It is a strange convention and it is the one every doctor uses, so this site uses it too.
Do I have to sign up?
No. Every tool works fully without an email address, and nothing is held back behind a form. Your date is stored in your own browser so the site remembers it on your next visit. It is never sent anywhere unless you type it into the email signup yourself.
Is any of this medical advice?
No. These are calculators and checklists built on the standard dating conventions. They are useful for planning and useless as a diagnosis. Anything that worries you is a call to your midwife or doctor, not a search.