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Try an Example
Pick a scenario to see how the calculator works, then adjust the values
Due Date from LMP
Calculate the due date using the first day of the last menstrual period (10 weeks ago).
Key values: LMP method · 28-day cycle · Singleton
First Trimester Check
A pregnancy at approximately 8 weeks from conception date.
Key values: Conception method · 8 weeks ago · First trimester
Ultrasound Dating
Calculate timeline from an ultrasound performed at 12 weeks, 3 days.
Key values: Ultrasound method · 12w 3d at scan · 4 weeks ago
IVF Transfer Timeline
Estimate due date from a day-5 embryo transfer completed 14 days ago.
Key values: IVF method · Day-5 transfer · High confidence dating
This calculator is also known as Pregnancy Due Date Calculator.
Read the complete guideUnderstanding Due Dates
A due date is an estimate of when your baby will be born. Most pregnancies last around 40 weeks from the first day of your last menstrual period, but only about 5% of babies are born on their exact due date.
Examples
First Pregnancy Example
Sarah's last period started on January 1st. Her due date would be:
Adding 280 days (40 weeks) to January 1st gives a due date of October 8th.
Key takeaway: Most babies arrive within two weeks before or after the calculated due date.
Next Steps
Once you know your due date, it's important to schedule regular prenatal check-ups.
- Schedule your first prenatal appointment
- Start taking prenatal vitamins if you haven't already
Frequently Asked Questions about Pregnancy Due Date Calculator
How accurate is the due date calculation?
Due dates are estimates. Only about 5% of babies are born exactly on their due date, with most arriving within two weeks before or after.
Specialized Calculators
Choose from 4 specialized versions of this calculator, each optimized for specific use cases and calculation methods.
Method
3 CalculatorsAlternative methods and approaches
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