A 529 plan lets your college savings grow completely tax-free when used for education. Plug in what you've saved, what you can add each month, and how many years you have — and watch compounding do the heavy lifting. See your projected balance, how much is your own contributions versus tax-free growth, and whether you're on track for your goal.
Tax-free college savings growth
The magic of a 529 plan isn't the contribution — it's what happens to the growth. In an ordinary brokerage account, every dollar of gains and dividends gets nibbled by taxes along the way. Inside a 529, that growth compounds untouched, and when you pull it out for tuition, books, room and board, or even up to $10,000 of K-12 tuition, you pay zero federal tax on the earnings. Over fifteen or eighteen years, that tax-free compounding can mean tens of thousands of extra dollars in the account — money that would otherwise have leaked away to the IRS.
Time is the other half of the equation, and it's why parents who start early win so decisively. A modest $300 a month started when a child is born has nearly two decades to grow; the same amount started in high school barely has time to do anything but pile up as raw contributions. The chart below splits your projection into two parts — the money you put in versus the growth that money earned — so you can literally see compounding take over the longer your time horizon runs.
On top of the federal break, more than 30 states offer a state income-tax deduction or credit for 529 contributions, which is essentially free money for residents. The figures here are a projection based on a steady average return; real markets bounce around year to year, so treat the result as a planning target rather than a promise. If you're behind your goal, the fix is usually simple: start sooner, add a little more each month, or stretch the timeline.
Earnings inside a 529 are never taxed when spent on qualified education — unlike a regular brokerage account.
The earlier you open it, the more of your final balance comes from growth instead of your own pocket.
Most states add an income-tax deduction or credit for contributions — check your home state's plan first.
A 529 plan grows tax-free and withdrawals are untaxed when spent on qualified education expenses, which makes it the most efficient education savings vehicle in the US. The arithmetic is a standard future value projection; what distinguishes 529s is the surrounding rules. Many states offer a deduction or credit for contributions to their own plan. Contributions count as gifts, so the annual exclusion applies, though a five-year front-loading election permits a large single contribution. And since 2024, unused balances can be rolled to a Roth IRA for the beneficiary within limits, which removes the main historical objection.
FV = P(1 + r)^n + PMT × [ ((1 + r)^n − 1) ÷ r ]Non-qualified withdrawal: earnings taxed as income + 10% penaltyFive-year election: contribute 5× the annual gift exclusion at onceRoth rollover: lifetime cap of $35,000, account open 15 yearswhere:
Assumptions: Assets count against financial aid, though at the favourable parental rate of up to 5.64% when parent-owned. K-12 tuition is qualified up to $10,000 a year federally, but not in every state.
Project a monthly contribution and compare it with the tax cost of a taxable account.
Result$116,206 at 18 — with $7,711 of tax avoided
The tax saving grows with the time horizon and the return, so starting at birth rather than age 8 roughly triples the benefit. Add any state deduction on top: a 5% state benefit on $64,800 of contributions is a further $3,240.