PREGNANCY
Estimate a pregnancy due date from the first day of your last period or a known conception date.
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FREE PREGNANCY DUE DATE CALCULATOR
Use the first day of your last period or a known conception date to calculate an estimated due date and pregnancy timeline.
*The information submitted in this calculator is not stored.
This is an estimateThe last-period method adds 40 weeks and assumes a typical 28-day cycle. Cycle length and ovulation timing vary, so your gynaecologist may confirm a different date.
Pregnancy after IVF needs different datingIVF due dates use the egg-retrieval or embryo-transfer date and embryo age. Use the date confirmed by your fertility clinic.
A HELPING HAND FOR WHAT COMES NEXT
Talk through the estimate with Aura, or keep it with your dates so it is easy to find next time.
Create a free ParentAura+ App account to keep this dated result, follow changes and build a clearer report over time.
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WHAT YOUR ESTIMATE SHOWS
USEFUL TO KNOW
This is an estimation based on the details entered. Please consult your gynaecologist to confirm the outcome when it relates to your care.
ABOUT YOUR ESTIMATED DUE DATE
A due date gives you and your care team a useful pregnancy timeline. It helps organise appointments and understand gestational age throughout pregnancy.
The most common calculation begins with the first day of your last menstrual period, often shortened to LMP. It adds 280 days, or 40 weeks, to that date. This method assumes a cycle of about 28 days with ovulation near day 14.
The calculator adds 266 days, or 38 weeks, to a known conception date. In natural conception, the exact date can be difficult to know because sperm can survive for several days and ovulation may change from one cycle to another.
When cycle length varies or the last-period date is uncertain, an early ultrasound may give your clinician a more appropriate dating estimate.
IVF pregnancy dating uses the egg-retrieval or embryo-transfer date and the embryo’s age. A general LMP or conception calculator is not the correct method; follow the date given by your fertility clinic.
Gestational age is counted from the start of the last period. In a typical cycle, this includes roughly two weeks before fertilisation. This standard approach gives clinicians one consistent pregnancy timeline.
It is a planning estimate. Pregnancy length naturally varies, and only a small proportion of babies arrive on the exact calculated date. Your gynaecologist may review your menstrual history and an early ultrasound before confirming the estimated due date used for your care.
Once an estimated date is confirmed, it helps the care team understand how many weeks pregnant you are and plan time-sensitive antenatal care. It should not be changed casually because different dates can make the pregnancy timeline confusing.
EDD means estimated due date. It is the reference date used to understand gestational age and plan pregnancy care.
Gestational age is conventionally counted from the first day of the last menstrual period. In a typical cycle, the 40-week timeline therefore includes roughly two weeks before conception.
An early ultrasound can provide a more reliable dating estimate, particularly when period dates are uncertain or cycles are irregular. Your maternity professional will confirm the date used for your care.
IVF dating uses the egg-retrieval or embryo-transfer date together with the embryo’s age. Follow the estimated due date confirmed by your fertility clinic.
It can estimate your due date, completed pregnancy weeks, approximate month and trimester, then keep the dates you choose to add together in your private dashboard.
A HELPING HAND FOR FUTURE DATES
The matching ParentAura+ App keeps the dates and updates you choose to add together, so your own pattern becomes easier to follow over time.
FREQUENTLY ASKED QUESTIONS
No. Every calculator gives its result without asking for an account or contact details.
No. Your entries stay in the browser while you calculate and are not automatically added to a ParentAura profile.
You can leave with the result, talk it through with Aura, or explicitly save it to a free ParentAura+ Account for ongoing tracking.
No. Calculators provide mathematical estimates and general planning information. A qualified medical professional provides diagnosis and treatment.