This calculator is developed by an algorithm that allows you to know when you can expect your baby to arrive after nine months providing the date estimate of conception.
The estimated due date is the spontaneous date that one expects labor to occur. The due date may be estimated by adding 280 days to the first day of the last menstrual period if the conception date is unknown. We assume that regular cycles are comprised of 28 days, and that conception occurs on the 14th day of the cycle. In cases where the date of conception is known precisely, such as with in vitro fertilization, the estimated due date is calculated by adding 266 days to the date of conception.
Note that this calculator is not very reliable and the dates are just an estimation. The due date can occur before or after the expected date of labor.