How this calculator works
This calculator estimates due date, conception date, and gestational age from the first day of the last menstrual period. Enter the last period date and average cycle length to see the estimates. Use it for pregnancy planning, tracking gestational age, and understanding pregnancy timelines. The key inputs are the first day of the last period and the average cycle length in days. The output is the estimated due date, conception date, and current gestational age. Real-world applications include pregnancy planning, healthcare conversations, family planning, and timeline tracking. The calculator adds 280 days to the last menstrual period, adjusted by the difference between the entered cycle length and 28 days. Due dates are estimates, not deadlines. Many babies arrive before or after the calculated date. Confirm dates with a healthcare professional or ultrasound when needed.