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Due Date Calculator
Estimate your baby's due date from your last period or conception date — and see where you are today.
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Understanding Your Due Date
The due date is an estimate — only around 4% of babies arrive on their exact due date. A pregnancy is considered full term from 37 to 42 weeks.
- Early term — 37 to 38 weeks.
- Full term — 39 to 40 weeks.
- Late term — 41 weeks.
- Postterm — 42 weeks and beyond.
Frequently Asked Questions
Which method is more accurate?
If you are sure of your conception date, it is slightly more precise. Otherwise LMP plus 280 days is standard.
Can the due date change?
Yes — an early ultrasound is the most reliable dating method and may adjust the estimate by days or weeks.
What if my cycles are irregular?
Ultrasound dating becomes even more important. Share your cycle length with your provider.
Is this medical advice?
No. Use this as a planning estimate and rely on your healthcare provider for clinical dating.
Practical Example
If you conceive on July 5:
- By conception date + 266 days → due ≈ March 28
- By the LMP method (if LMP = June 21) → due ≈ March 28 (matching)
Both methods usually agree within a few days when the cycle is regular.
What Your Results Mean
- Conception date method — more precise when you know the exact date.
- LMP method — the standard clinical default of 280 days from the last period.
- An early ultrasound remains the most accurate dating method overall.
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