Due date calculator
Free pregnancy due date calculator. Estimate your due date from your last period, conception, IVF transfer, or ultrasound, and see how far along you are today.
How to use
- Choose a starting point. Pick the method you have information for: last period, conception date, IVF transfer, or ultrasound.
- Enter your date. Add the relevant date, such as the first day of your last period or your embryo transfer date.
- Adjust cycle length if needed. If you are using your last period, set your average cycle length so the estimate can be fine-tuned from the default 28 days.
- Read your results. See your estimated due date, how far along you are, your conception date, and your current trimester instantly.
Features
- Four dating methods. Estimate from your last period, conception date, IVF transfer, or ultrasound, whichever suits your situation.
- How far along you are. Shows your progress today in weeks and days, not just a single due date months away.
- Trimester breakdown. Tells you which trimester you are in and when the next one begins.
- Cycle-length adjustment. Lets you set a cycle length other than 28 days for a more personal estimate from your last period.
- Conception date estimate. Works backward to show your likely conception date alongside your due date.
When to use it
- Estimating your due date early in pregnancy before your first scan.
- Checking how many weeks and days along you are right now.
- Working out a due date from an IVF embryo transfer date.
- Finding your likely conception date from your last period.
- Planning appointments and milestones around your trimesters.
Is it private?
Everything runs entirely in your browser, and nothing you enter is ever sent to a server.
Frequently asked questions
Is this due date calculator free?
Yes, it is completely free with no sign-up, no limits, and no install required.
How is my due date calculated?
For a last-period estimate the tool uses Naegele's rule, adding 280 days (40 weeks) to the first day of your last period, adjusted for your cycle length. Conception, IVF, and ultrasound methods count forward from their own reference points.
Will my baby be born on the due date?
Almost certainly not on that exact day. Only about 4 percent of babies are born on their due date; most arrive in the two weeks before or after, so treat it as the middle of a likely window.
How accurate is this estimate?
It is a good general guide, but a dating ultrasound performed by your provider is more accurate, especially if your cycles are irregular. Always defer to the date your doctor or midwife gives you.
Which method is most reliable?
If you know your conception, IVF transfer, or ultrasound date, those tend to be more precise than a last-period estimate, which assumes a regular cycle and ovulation on day 14.
Do you store my dates?
No. Everything is calculated in your browser and nothing you enter is sent to or saved on a server.
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