Pregnancy Due Date Calculator
Enter the first day of your last period or conception date to estimate your due date, trimester timeline, and key milestones.
How Due Dates Are Calculated
The standard calculation uses Naegele rule: add 280 days (40 weeks) to the first day of your last menstrual period (LMP). This assumes a 28-day cycle with ovulation on day 14. If your cycle is longer or shorter, the calculator adjusts — a 35-day cycle shifts the due date 7 days later. Only about 5% of babies arrive on their actual due date. The normal range is 37-42 weeks, with most births occurring between 39-41 weeks.
Pregnancy Timeline & Milestones
Week 6: Heartbeat detectable on ultrasound. Week 12: End of first trimester — miscarriage risk drops significantly. Week 20: Anatomy scan (gender reveal if desired). Week 24: Viability milestone — survival outside the womb becomes possible with NICU care. Week 28: Third trimester begins. Week 37: Early term — lungs usually mature. Week 39: Full term — ideal delivery window. Week 40: Due date. Week 41+: Post-term — induction typically discussed.
Due date calculator is one of the most emotionally significant searches a person makes — 130K+ monthly. Users return repeatedly throughout pregnancy to check their current week. Average session: 4+ minutes with high engagement on milestone information. This page has excellent potential for related content linking to baby budget, nursery planning, and pregnancy nutrition calculators.
