Pregnancy Due Date Calculator

Tracking your pregnancy is simple:

Step 1: Select the first day of your last menstrual period (LMP).

Step 2: Enter your average cycle length (standard is 28 days).

Step 3: Calculate to view your Due Date, Gestational Age (weeks/days), and current Trimester.

Step 4: Check the 'Baby Size' visual comparison and the detailed trimester timeline to see when your next milestones occur.

Due date is calculated using Naegele's rule: LMP + 280 days (40 weeks). We refine this by adjusting for your specific cycle length. For example, if your cycle is 30 days, we add 2 extra days to the standard calculation. Conception is estimated as LMP + (Cycle Length - 14 days).

Calculating your estimated due date (EDD) is one of the first and most important steps in prenatal care. This calculator uses Naegele's Rule — the global medical standard for due date estimation — which adds 280 days (40 weeks) to the first day of your last menstrual period (LMP). The 40-week timeline is divided into three trimesters, each representing distinct and critical stages of fetal development.

The tool adjusts for your individual cycle length, because ovulation and therefore conception typically occurs about 14 days before the end of a cycle. A 30-day cycle, for example, shifts the estimated due date forward by 2 days compared to the standard 28-day baseline calculation.

Important medical disclaimer: Only about 4–5% of babies are born on their exact due date. The EDD is an estimated midpoint of a 5-week window (weeks 38–42) during which most full-term deliveries occur. Always confirm your due date with an obstetrician, ideally via first-trimester ultrasound, which is the most accurate dating method available.