Pregnancy Due Date Calculator
Calculate your estimated due date, current pregnancy week, trimester, and important milestones. Multiple calculation methods including last menstrual period, conception date, IVF transfer, and ultrasound dating.
âš This calculator provides estimates only. Please consult your healthcare provider for medical guidance.
All calculations happen in your browser. No data is sent to any server.
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How to Use
- 1 Select calculation method — Choose how you want to calculate: Last Menstrual Period (most common), Conception Date, IVF Transfer Date, or Ultrasound Date.
- 2 Enter the date — Select the relevant date based on your chosen method. For LMP, enter the first day of your last period.
- 3 Adjust settings if needed — For LMP method, adjust your cycle length if it differs from 28 days. For ultrasound method, enter the gestational age at the time of the scan.
- 4 View your results — See your estimated due date, current week and day of pregnancy, trimester, and days remaining.
- 5 Review milestones — Check key pregnancy milestones including end of each trimester, viability milestone, and full term date. Add the due date to your calendar.
Frequently Asked Questions
How accurate is the due date calculation?
Due dates are estimates based on a typical 40-week pregnancy. Only about 5% of babies are born on their exact due date. Most babies arrive within 2 weeks before or after the estimated date. Your healthcare provider may adjust the date based on ultrasound measurements, especially during the first trimester when dating is most accurate.
What's the difference between LMP and conception date?
LMP (Last Menstrual Period) counts pregnancy from the first day of your last period, assuming a 28-day cycle. Conception typically occurs about 2 weeks after LMP during ovulation. Both methods should give similar due dates when calculated correctly. The LMP method is most commonly used as it's easier for most women to recall.
How are trimesters divided?
The three trimesters divide the ~40 weeks of pregnancy: First trimester (weeks 1-12) covers initial development and organ formation; Second trimester (weeks 13-26) involves rapid growth and movement; Third trimester (weeks 27-40) is the final growth phase as baby prepares for birth. Each trimester brings different developmental milestones and physical changes.
What is the viability milestone?
Around 24 weeks, a baby reaches viability — the point at which survival outside the womb becomes possible with intensive medical care. While outcomes at this stage require significant intervention, survival rates improve significantly with each additional week of pregnancy. This is an important milestone tracked by healthcare providers.