When is your baby due?
From the first day of your last period, this calculator gives your estimated due date, how far along you are today, and your trimester milestones — adjusted for your cycle length.
Calculate your due date
Naegele’s rule, properly adjusted
The estimated due date (EDD) uses Naegele's rule: LMP + 280 days (40 weeks). Because that rule assumes ovulation on day 14 of a 28-day cycle, we adjust by your actual cycle length — a 32-day cycle shifts the EDD 4 days later, which matters for accurate dating.
Only about 4–5% of babies arrive exactly on their due date; most arrive within two weeks either side. Your obstetrician will refine dating with a first-trimester ultrasound (the most accurate method) — this calculator is the right starting point for planning that first antenatal visit, ideally before 10 weeks.
These results are indicative wellness estimates based on standard published formulas — not a diagnosis or medical advice. Always consult your doctor for clinical decisions. Book your first antenatal visit early — ultrasound dating before 14 weeks is the most accurate.
Frequently asked questions
Within about ±2 weeks for most pregnancies with regular cycles. A first-trimester ultrasound is more accurate and will be used by your obstetrician to confirm or adjust the date.
LMP-based dating becomes unreliable with irregular cycles — book an early dating ultrasound instead, and mention the irregularity to your gynecologist.
No — the calculation happens entirely in your browser. Nothing is transmitted or saved.
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