How the projection works
The calculator builds two numbers and compares them. The savings goal grows today's annual college cost by education-cost inflation to each year your child is enrolled, sums those years, and keeps the share you choose to cover. The projected balance grows your current 529 balance at an assumed return and adds your monthly contributions, compounded monthly, until enrollment. The gap between the two, and the monthly amount that closes it, are the figures that drive the plan.