How this calculator works
This calculator estimates the expected due date from the first day of the last menstrual period and average cycle length. Enter the last period date and cycle length to see the estimated due date. Use it for pregnancy planning and understanding expected 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. Real-world applications include pregnancy planning, healthcare scheduling, family planning, and calendar planning. The calculator adds 280 days to the first day of the last period, adjusted by cycle length. If cycles are irregular, date-based estimates are less precise. A healthcare professional can provide a more reliable estimate. The due date is an estimated midpoint, not a deadline. Birth timing varies naturally.