Enter your child's age, your balance and monthly contribution, and today's college cost. You'll get the projected balance at college start, a year-by-year drawdown showing exactly which years it covers, and the monthly amount that would cover everything.
A race between three rates
Every 529 projection is the same race: your investment return versus college cost inflation, with time deciding the winner. College costs have outrun ordinary inflation for decades (about 4% a year is the honest planning assumption, even though recent years ran cooler), and a diversified 529 has historically earned more than that, which means time in the account is the whole ballgame. A dollar contributed at age 3 fights fifteen rounds; a dollar at 16 barely gets its gloves on.
This calculator runs the race properly: it compounds your balance and monthly contributions to the first day of college, escalates today's cost to what tuition will actually charge by then, and then, unlike the simple ratio most tools show, simulates the four years of drawdown, because the money still invested keeps growing while your student studies, and that quietly stretches the balance further than a straight division suggests.
The formula
Balance at 18 = P(1 + r/12)12t + m × [(1 + r/12)12t − 1] / (r/12)
Cost in year k = Today's cost × (1 + c)t + k
P is today's balance, m the monthly contribution, r the annual return, c college inflation, t years until college. The drawdown then withdraws each year's cost and grows the remainder at the same return, which is a stated simplification: age-based portfolios de-risk near college, so late-stage returns typically run below the long-term average.
Worked example
A 3-year-old, a $10,000 balance, $500 a month, 6% return. By 18 the account holds $169,950.29: $100,000 put in, $69,950.29 of tax-free growth.
A $30,000 public in-state cost today at 4% inflation reaches $54,028.31 by freshman year: $229,429.26 across four years. The drawdown covers freshman through junior year in full and $12,987.25 of senior year, leaving $47,787.25 to financial aid, current income, and scholarships. Covering everything from savings alone would have taken about $637.97 a month: $138 more than the plan, or the same $500 started three years earlier.
The modern 529 is better than its reputation
Two old fears about 529s died recently, and plenty of parents have not heard. The first: "what if my kid does not use it?" Since 2024, leftover 529 money can roll into the beneficiary's own Roth IRA: up to $35,000 lifetime, once the account is 15 years old, at the annual Roth contribution pace. An overfunded 529 is no longer trapped money; it is a head start on your child's retirement. The second: "it is only for college." As of this year the K-12 withdrawal allowance doubled to $20,000 per year and the qualified list grew to include tutoring, curriculum materials, standardized test fees, and educational therapies, though a number of states have not conformed their own tax rules to the federal change, so check yours before a big K-12 withdrawal.
Two more levers worth knowing. Over thirty states offer a state tax deduction or credit for 529 contributions, which is an immediate return before a dollar is invested; the catch is usually that you must use your own state's plan to get it. And grandparents holding money for the cause should know about superfunding: the five-year gift election lets one person contribute $95,000 at once (a couple, $190,000) with no gift-tax consequences, and the earlier those dollars land, the more rounds they fight. Under current FAFSA rules, distributions from grandparent-owned 529s no longer count against the student's aid, which quietly made that the most generous move in the family playbook.
Frequently asked questions
How much should I put in a 529 per month?
Work backwards from coverage: in this page's example, covering a full public in-state degree from age 3 takes about $638 a month, while $500 covers three years and most of the fourth. Most families deliberately target partial coverage and let aid, income, and scholarships carry the rest, which is a plan, not a failure.
How fast do college costs actually grow?
Around 4% a year is the honest long-run planning assumption, though recent years ran closer to ordinary inflation. All-in costs today average about $30,000 a year for public in-state students and $63,000 at private colleges, and the calculator escalates whichever figure you enter.
What return should I assume for a 529?
A flat 5% to 6% is a reasonable planning figure, with one honest caveat: age-based portfolios deliberately shift toward bonds as college nears, so late-year returns typically run below the long-term average. That is why the projection here should be read as a good map rather than a promise.
What happens to leftover 529 money?
The modern answer changed everything: up to $35,000 of leftover funds can roll into the beneficiary's own Roth IRA over time, once the account is 15 years old, at annual Roth contribution limits. Beyond that, you can change the beneficiary to another family member, use it for graduate school, or withdraw earnings with tax plus a 10% penalty as the last resort.
Can a 529 pay for K-12 school?
Yes, and the allowance doubled to $20,000 per year starting in 2026, with the qualified list expanded to tutoring, curriculum materials, standardized test fees, and educational therapies. One catch: several states have not conformed their tax rules to the federal change, so check your state before making a large K-12 withdrawal.
What is 529 superfunding?
A five-year gift election that lets one person contribute five years of annual exclusions at once: $95,000 in 2026, or $190,000 from a couple, with no gift tax consequences. Front-loading matters because the earliest dollars compound longest; it is the classic grandparent move.
Do 529 plans hurt financial aid?
Parent-owned 529s count modestly in the federal aid formula (a maximum of 5.64% of the balance), far more gently than student-owned assets. Grandparent-owned 529s stopped counting against the student entirely under current FAFSA rules, which quietly made grandparent accounts the most aid-friendly way to help.
Do I get a tax break for contributing?
Federally, no deduction going in; the benefit is tax-free growth and tax-free qualified withdrawals. But over thirty states offer a deduction or credit for contributions, usually only through the home state's own plan, which is effectively an instant return and the first thing to check before picking a plan.
Is it too late to start a 529 for a teenager?
Later starts earn less compounding, but the state tax deduction, tax-free growth on whatever time remains, and the ability to keep the account running through all four college years (money for senior year has seven more years to grow than freshman-year money) still make it worthwhile. The alternative, saving in a taxable account, gives up those edges.