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Estimate your baby's arrival due date, gestational development weeks, trimesters, and key pregnancy milestones.
Select the first calendar day of your last normal menstrual cycle.
Estimated 40-week milestone based on Naegele's 280-day gestational rule.
Week 35
32 Days
January 15, 2026
Ovulation and fertilization window.
Cardiac activity detectable via ultrasound.
Critical organogenesis completed.
Fluttering baby movements may be felt.
Detailed mid-pregnancy anatomical scan.
Lungs begin developing surfactant.
Rapid brain and weight growth stage.
Baby considered full term.
Official 40-week delivery milestone.
Obstetric timeline schedule computed via Naegele's Rule.
Print gestational statement, export milestone calendar to CSV/JSON, or copy summary notes.
Pregnancy Due Date & Gestational Age Calculator. Calculate your estimated date of delivery (EDD), current gestational week, and developmental milestones based on your last menstrual period. ZechKit provides this tool completely free and online, optimized for instant, accurate computations directly inside your web browser.
A Pregnancy Due Date Calculator estimates your delivery date (EDD) and tracks fetal gestational development based on the start of your last menstrual period (LMP).
Naegele's Rule: Due date is calculated by adding 280 days (40 weeks) to the first day of your last menstrual period, adjusted for variations from a standard 28-day cycle.
Trimester Milestones: First Trimester (Weeks 1 to 13), Second Trimester (Weeks 14 to 27), and Third Trimester (Weeks 28 to 40+).
Clinical Dating: Most full-term births occur between 37 and 42 weeks; clinical ultrasound dating in the first trimester provides the most accurate confirmation of gestational age.
How does Naegele's Rule calculate an estimated due date?
Naegele's rule projects 280 days (40 completed weeks) forward from the first day of your last menstrual period to estimate delivery timing.
