Last period date
The first day of your last period is the standard starting point for a simple due date estimate.
Due date calculator
Due DateCalculator
Estimate your baby due date, current pregnancy week, and likely conception date from the first day of your last period.
This calculator uses LMP dating, supports cycle lengths from 22 to 44 days, and estimates pregnancy over a 40-week timeline. Due dates are estimates. Your doctor may update the timeline using ultrasound dating, IVF transfer details, symptoms, or clinical history.
Calculate your expected delivery date
Enter the first day of bleeding from your most recent period and your usual cycle length.
Enter your last period date to see your estimated due date.
Unsure about your dates or tracking a fertility-treatment pregnancy? A Pluro specialist can help plan the right scan and follow-up.
Guide
What affects a due date estimate?
Average cycle length
Cycle length helps adjust likely ovulation timing when your usual cycle is not 28 days.
Clinical dating
Ultrasound findings, IVF transfer details, and symptoms can help your doctor confirm or revise dates.
Common questions
Due date calculator FAQs
How does a due date calculator work?
A due date calculator usually estimates 40 weeks of pregnancy from the first day of your last menstrual period and adjusts for average cycle length.
Is the calculated due date exact?
No. It is an estimate. Your doctor may update the due date after ultrasound dating or based on IVF transfer details and clinical history.
What if I do not know my last period date?
If you are unsure about the last period date, ultrasound dating or fertility treatment records may give a more useful estimate.
Can cycle length change the result?
Yes. Longer or shorter cycles can shift likely ovulation and may shift the estimated due date compared with a standard 28-day cycle.
Need more context?
Use the full pregnancy calculator
If you conceived through IVF or have an ultrasound report, the pregnancy calculator can use those details.