Calculate Your Due Date,
Know Your Countdown.
Free pregnancy calculators: estimated due date from LMP or conception, current week and trimester, IVF transfer dates, and countdown milestones.
IVF & Ovulation Precision
Exact date adjustments for 3-day or 5-day blastocyst embryo transfers and tracked ovulation.
Week-by-Week Development
Clear markers for organogenesis, anatomy scan timing, and full-term viability thresholds.
4% Exact Day Reality
Only 4% of infants arrive on their exact predicted date; 80% deliver within ±2 weeks.
DueDateCalc Calculators
Due Date Calculator
Estimated due date from last menstrual period (with cycle-length adjustment) or conception date — standard obstetric math.
Pregnancy Week Calculator
Where you are right now: gestational week, day, trimester, and the weeks remaining — from your due date or LMP.
IVF Due Date Calculator
Due date from embryo transfer date — 3-day or 5-day transfer — the most precise dating method that exists.
Conception Date Estimator
The likely conception window from a due date or LMP — with the fertile window that produced it.
Evidence-Based Physiology
Why your due date will probably change — and why that is fine
LMP dating vs ultrasound dating, the re-date rules, and the psychology of a moving finish line.
The third-trimester countdown: what the week counter is actually tracking
From viability to full term to 42 weeks — what each milestone means clinically.
12 mistakes people make with pregnancy dating
The recurring errors we see in pregnancy dating — what causes each one, and the habit that prevents it.