CalcInfinityPregnancy Due Date Calculator
Estimate your due date and see how far along you are — from your last period, conception date, or IVF transfer date.
Worked Example — LMP of January 1, 2026
Frequently Asked Questions
The due date formula is the same regardless of how many babies you're expecting. In practice, twin pregnancies often deliver before the estimated due date, so treat this as an even more approximate estimate for twins.
Common Mistakes to Avoid
- Only about 5% of babies are born on their exact due date. This is a helpful estimate based on averages, not a guarantee. An ultrasound in the first trimester is considered the most accurate way to date a pregnancy — always confirm your estimate with your doctor.
- This isn't medical advice — it's a scheduling estimate. Use this to get a general sense of timing and gestational age, not to make clinical decisions. Your doctor's dating (especially from an early ultrasound) takes precedence over this calculator's estimate.
References
- ACOG (American College of Obstetricians and Gynecologists) — trimester boundaries and standard 280-day (Naegele's rule) due date estimation
Last reviewed July 2026
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