Finding out you are pregnant brings a rush of questions, and the first one is usually the same: when is my baby due? Our free Pregnancy Due Date Calculator gives you a clear answer in seconds. Choose how you want to calculate, enter a few simple details, and you will instantly see your estimated due date, how many weeks pregnant you are today, which trimester you are in, and how many days remain until your baby is expected.
Pregnancy Due Date Calculator
A typical pregnancy lasts about 40 weeks, or 280 days, counted from the first day of your last menstrual period. This calculator uses that standard method, known as Naegele’s rule, and improves on it by adjusting for your own cycle length. If your cycle is longer or shorter than 28 days, ovulation usually happens later or earlier than average, so your due date shifts with it. Enter your real cycle length and you get a more personal estimate than a simple “add nine months” rule.
Not everyone knows the date of their last period, and that is fine. This tool offers four ways to calculate your due date. Use the last period method if you track your cycles. Use the conception date method if you know when you conceived, for example from ovulation tracking. If you conceived through IVF, choose the embryo transfer option and select a 3-day or 5-day embryo for a precise estimate. If an ultrasound has given you the age of your pregnancy, enter the scan date and the weeks and days measured, and the calculator works out your due date from that.
Along with your due date, you receive a simple timeline of important pregnancy milestones. You can see when the second trimester begins at week 14, the usual window for the mid-pregnancy anatomy scan between weeks 18 and 22, the 24-week viability milestone, the start of the third trimester at week 28, and the weeks when your baby is considered early term, full term and late term. Dates that have already passed are shown in grey, so you can see at a glance where you are on your journey.
It is important to remember that a due date is an estimate, not a deadline. Only a small percentage of babies arrive exactly on their due date. Most are born between 37 and 42 weeks, and many first-time parents deliver a little later than expected. Your doctor or midwife may adjust your due date after an early ultrasound, because scan measurements in the first trimester are considered very accurate. Treat the result as a helpful planning guide and always follow the advice of your healthcare provider.
Knowing your due date helps with practical planning. You can book prenatal appointments, schedule screening tests, plan maternity or paternity leave, prepare your home, choose a hospital or birth center, and share the news with family at the right time. Many expectant parents also use the date to follow week-by-week pregnancy guides and track their baby’s development.
The Pregnancy Due Date Calculator is completely free, requires no registration, and works on phones, tablets and computers. Everything is calculated directly in your browser, so the dates you enter are not stored or sent anywhere. You can calculate as many times as you like, change the method, and use the Share Results button to send your due date to your partner, family or friends.
Whether you are newly pregnant, planning ahead or simply curious, this calculator gives you a fast, friendly and reliable estimate. Enter your details above, click Calculate, and start counting down the exciting weeks until you meet your precious little one.
How to Use
- Choose a method: last period, conception date, IVF embryo transfer or ultrasound scan.
- Enter the date, plus your cycle length, embryo age, or the weeks and days measured at your scan, depending on the method.
- Click Calculate to see your due date, pregnancy age, trimester, countdown and milestone dates.
- Click Share Results to share or copy your due date, or Reset to start again.
FAQs
- How is the due date calculated? It is 280 days (40 weeks) from the first day of your last period, adjusted for your cycle length. The other methods use the same 40-week timeline from conception, embryo transfer or scan data.
- Is my due date exact? No. It is an estimate, and most babies are born between 37 and 42 weeks.
- Which method is most accurate? An early ultrasound is generally considered very accurate. Your doctor or midwife may adjust your due date based on it.
- Is my data saved? No. Everything is calculated in your browser.
