College Savings & 529 Growth Calculator

Compounding a 529 from a seed balance and monthly contributions

Starting with $5,000 and contributing $250/month for 12 years at an assumed 6% annual return, the projected balance reaches $62,791.29. Total contributions over that period -- the $5,000 seed plus $250 x 144 months -- add up to $41,000.00, meaning $21,791.29 of the final balance is investment growth rather than money you put in.

That growth share (about 34.7% of the final balance) grows faster the longer the time horizon runs, since compounding needs years to build momentum -- a 6-year-old's 529 has more room to compound than a 15-year-old's.

The formula compounds monthly: each month's contribution earns the assumed rate for every remaining month in the 12-year window, so contributions made in year one earn far more total growth than contributions made in year eleven.

The assumption doing the most work

Constant return assumption. Not a plan prospectus or tax advice. Real markets don't return a flat 6% every year -- some years are up 20%, some are down 15%, and the order those returns happen in (not just the average) affects the final balance in ways this simplified model can't capture.

529 plans have real tax advantages (tax-free growth and withdrawal for qualified education expenses) that this calculator doesn't quantify -- it only shows the growth math, not the tax benefit on top of it.

Years must be greater than zero for the projection to run; a zero-year input has no compounding period to work with.

Comparing this to other ways to save the same amount

For a shorter, non-education goal with the same monthly-contribution structure, the Sinking Fund Savings Calculator uses simpler math without an assumed market return.

If you're deciding between a 529 and a taxable brokerage account for this money, compare the growth-plus-dividends path on the Dividend Reinvestment (DRIP) Calculator.

Frequently Asked Questions (FAQ)