What is it?
The Pregnancy Due Date Calculator estimates when your baby is due. It also shows how many weeks pregnant you are today, the days to go and roughly when conception happened.
Who is it for?
Expecting parents, family members, and anyone wanting a quick estimate of the due date and pregnancy week.
How to use it
Enter the First day of your last period and your Usual cycle length (28 days if you are not sure). The answer appears as you type; there is no Calculate button. Tap Copy result to copy it, or Share on WhatsApp to send it.
How it is worked out
Doctors count 40 weeks (280 days) from the first day of the last period, for a 28-day cycle (Naegele’s rule). Longer or shorter cycles move the date by the difference, which the calculator applies.
Why the scan date can differ
- “Only about 1 in 20 babies arrive on the due date; most come within two weeks of it. Your doctor or midwife may adjust it after a scan”
- An early dating scan (around 8–13 weeks) is the most accurate way to date a pregnancy, especially with irregular cycles.
- Pregnancies after IVF are dated from the embryo transfer date.
Weeks and trimesters
Weeks 1–13 are the first trimester, 14–27 the second, and 28 to birth the third. “Weeks pregnant” counts from the last period, so in week 4 conception happened about two weeks earlier.
This is general information to help you understand your numbers, not medical advice. Talk to a doctor about your own health.
Errors and how to fix them
- “Choose a date”: enter the first day of your last period.
- Date in the future: check the year.
Open the tool: Pregnancy Due Date Calculator
Still stuck?
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Questions, or an error not listed here?
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