Pregnancy+ from Philips is the most downloaded pregnancy tracker in the world, and for good reason. But the very first question every pregnancy raises is a simple one: when is this baby due? Answering it should not require creating an account, downloading a 200 MB app, or agreeing to a privacy policy. So we built a due date calculator that runs right here in your browser. It is free, works on your phone, and keeps every date you enter on your own device.
Calculate your due date
Pick a dating method, set your date, and the results update as you type.
Your inputs are saved in your browser’s local storage so the calculator remembers where you are next visit. Nothing is uploaded, there is no account, and the “Clear my data” button wipes everything in one tap.
How the calculator works
The default method uses Naegele’s rule: your due date is 280 days after the first day of your last menstrual period. That rule quietly assumes a 28-day cycle with ovulation on day 14, which is why the calculator has a cycle length stepper. If your cycles run 33 days, ovulation likely happens later, so the estimate shifts about five days forward. Shorter cycles shift it back the same way.
If you know your conception date, the calculator counts 266 days from there instead, which skips the cycle assumption entirely.
IVF pregnancies get the most precise dating of all, because the embryo’s age is known exactly. For a day 3 transfer the calculator adds 263 days to the transfer date, and for a day 5 transfer it adds 261 days. Pick the option that matches your transfer and the cycle stepper disappears, since it no longer applies.
Whichever method you use, treat the result as a well-informed estimate. Your first ultrasound gives your care team a more direct measurement, and their dating is the one that counts.
How it compares to Pregnancy+
Our calculator answers one question well. Pregnancy+ is built for the other nine months.
The Philips app includes lifelike 3D models of your baby’s development, daily expert articles, a kick counter, a contraction timer, hospital bag checklists, and a personal timeline you can share with a partner. None of that lives in our calculator, and we are not pretending otherwise. If you want a daily companion through pregnancy, a dedicated app earns its place on your home screen.
Where the browser tool wins is speed and privacy. There is nothing to install, no registration screen, and no data leaving your device. Health data deserves that kind of caution by default, which is the same reason we built a private cycle tracker that runs in the browser. Use the calculator to get your date and your milestone timeline in ten seconds. Get the full app when you want everything else.
Get the full app
Pregnancy+ is free to download, with an optional premium tier that unlocks extra 3D content and features. It is available in over 20 languages and works without any Philips hardware.
Frequently asked questions
How accurate are due date calculators?
They are estimates, and honest ones say so. Only around 4 to 5 percent of babies arrive on their exact due date, and most are born within a two-week window on either side. Calculators based on your last period also depend on remembering that date correctly and on when you actually ovulated. Once you have a first-trimester ultrasound, its dating supersedes any calculator, including this one.
Is my data private?
Yes. The calculator runs entirely in your browser. The dates you enter are stored only in your browser’s local storage on your own device, and no information is sent to us or to anyone else. There is no account, no analytics, and no tracking inside the tool. The “Clear my data” button removes everything it saved.
Can this replace advice from my doctor or midwife?
No. This tool gives you a mathematical estimate and a rough milestone timeline, nothing more. It is not medical advice, it cannot account for your individual health situation, and it should never delay a conversation with a professional. Confirm your due date and every milestone with your healthcare provider.
Does it work for IVF pregnancies?
Yes, and IVF dating is actually the most reliable kind, because the embryo’s exact age is known. Choose the day 3 or day 5 transfer option that matches your treatment, enter the transfer date, and the calculator handles the rest. Your fertility clinic will give you the same date, so treat any difference as a sign to double-check your inputs.
Is this the official Pregnancy+ app?
No. Our calculator is an original tool built by the Unstore team, inspired by the core job a pregnancy tracker does on day one. It is not affiliated with, endorsed by, or connected to Philips or the Pregnancy+ app in any way. If you want the full Pregnancy+ experience, use the download links above to get the real thing.
