529 College Savings Calculator — will your savings meet the real cost

A 529 college savings calculator projects what your 529 plan balance will actually be worth by the time your child starts college, and compares it to what college is realistically going to cost by then — not what it costs today. That gap between "what you'll have" and "what you'll need" is the number every saving family actually needs to see.

Most parents anchor their savings target to today's tuition sticker price, but by the time a five-year-old reaches college, costs will have compounded upward for over a decade. This tool, provided free by Arb Digital, runs both projections side by side so you can see whether your current contribution rate is actually enough — and adjust early, while time is still on your side.

What This 529 College Savings Calculator Does

You enter your child's current age, the age they'll start college, your current 529 balance, your monthly contribution, an expected annual investment return, today's annual cost of the college you're planning for, an assumed college cost inflation rate, and the number of years they'll attend. The calculator compounds your existing balance and future monthly contributions forward at your expected return until the year college begins, then separately projects what the full multi-year cost of college will be once tuition inflation is applied year over year.

The result is a direct, honest comparison: your projected 529 balance against the projected total cost of the years of college you specified, with the surplus or shortfall shown as a single clear dollar figure.

How to Use It

1. Enter your child's current age and intended college start age. The difference is how many years your money has to grow.
2. Enter your current 529 balance and monthly contribution. Use $0 for balance if you haven't started yet.
3. Enter an expected annual return. A 529 invested in an age-based portfolio commonly assumes somewhere around 5-7% long-term, though your plan's actual mix may differ.
4. Enter today's annual cost for the type of college you're targeting. In-state public, out-of-state public, and private schools have very different sticker prices.
5. Enter an assumed college cost inflation rate and number of years of college. Four years is standard for a bachelor's degree.
6. Click Calculate and look at the surplus/shortfall number — if it's negative, you now know how much more you'd need to save monthly to close the gap.

The Formula / How It's Calculated

The 529 balance projection compounds your starting balance and adds your monthly contribution each month, applying your expected annual return divided into a monthly rate, for every month between now and your child's college start age. The college cost projection takes today's annual cost and grows it forward using the inflation rate you specify, compounded annually for the number of years until college starts; then it projects each of the college years forward from there, since costs keep rising during the years your child is actually enrolled, and sums those years into a total cost figure. The IRS treats 529 plans as tax-advantaged accounts under Section 529 of the tax code, and this calculator uses standard compound-growth mechanics to project both sides of the equation.

College Inflation Historically Outruns General Inflation

One of the most important things to understand about 529 planning is that the target keeps moving. College tuition and fees have, over long historical stretches, risen faster than the broader Consumer Price Index, meaning the sticker price you see today is very likely not the price your child will actually pay. If you only plan around today's cost, you're planning around a number that's already out of date by the time you need it. This is exactly why the calculator inflates both the starting-year cost and every subsequent year of enrollment — a shortfall that looks manageable using today's prices can look very different once realistic tuition inflation is applied across a decade or more.

The practical takeaway is to re-run this projection periodically, ideally once a year, and adjust your monthly contribution as your child gets closer to college age and actual costs become clearer.

Tax-Free Growth and Possible State Deductions

A 529 plan's core advantage is that investment growth inside the account is not taxed at the federal level, and withdrawals are entirely tax-free as long as they're used for qualified education expenses — tuition, fees, room and board, books, and certain other costs. Many states also offer a state income tax deduction or credit for contributions to their own state's 529 plan, which effectively gives you an immediate discount on the money you're putting away, on top of the tax-free growth. Because state rules vary widely, it's worth checking your own state's specific 529 program details before assuming a deduction applies, since some states offer no deduction at all while others are quite generous.

The 2024+ Rule: Leftover 529 Funds Can Roll Into a Roth IRA

Historically, one of the biggest hesitations around 529 plans was the fear of over-saving — what happens if your child gets a scholarship, doesn't attend college, or simply doesn't need all the money? Non-qualified withdrawals face income tax plus a 10% penalty on the earnings portion, which understandably made some families cautious about contributing aggressively. Starting in 2024, new rules allow beneficiaries to roll over up to a lifetime limit (currently $35,000) of unused 529 funds directly into a Roth IRA in the beneficiary's name, subject to annual Roth contribution limits and a requirement that the 529 account has been open for at least 15 years. This change meaningfully reduces the risk of over-funding a 529 plan, since leftover money no longer has to sit unused or face a penalty — it can instead jump-start your child's retirement savings. As always, confirm current details directly, since program rules can be updated by Congress.

• The Roth rollover has annual and lifetime caps — it's not an unlimited escape valve.
• The 529 account generally needs to have been open 15+ years to qualify.
• Scholarships also allow a penalty-free (though still taxable on earnings) withdrawal up to the scholarship amount.

Choosing an Investment Mix Inside Your 529

Most 529 plans offer age-based portfolios that automatically shift from growth-oriented investments toward more conservative holdings as your child approaches college age, similar in concept to a target-date retirement fund. Early on, when your child is young and the time horizon is long, a more aggressive allocation can capture more growth, since there's time to ride out market downturns. As college gets closer, shifting toward bonds and cash equivalents reduces the risk that a bad market year right before tuition is due wipes out years of gains. If your plan allows you to choose your own allocation rather than using the age-based default, it's worth reviewing it periodically rather than setting it once and forgetting it, especially as your child moves through elementary, middle, and high school.

The expected annual return you enter into this calculator should reflect your actual allocation, not an optimistic blended figure. A portfolio that's already shifted mostly into conservative holdings by the time your child is in high school will realistically grow more slowly than an all-equity portfolio would for a five-year-old, and using an overly rosy return assumption is one of the most common ways families overestimate their real progress.

What Counts as a Qualified Expense

Qualified 529 expenses go beyond just tuition. They generally include mandatory fees, room and board (for students enrolled at least half-time), required books and supplies, and computers or equipment required for enrollment. Some plans also allow a limited amount to be used for K-12 tuition or registered apprenticeship program costs, though limits and rules vary and have changed over time, so it's worth confirming current details for your specific plan and situation. Understanding the full scope of qualified expenses matters when you're estimating your true annual cost figure for this calculator — many families under-budget by focusing only on the tuition line item and forgetting room, board, and required supplies, which can easily add thousands of dollars per year at a residential four-year school.

Common Mistakes to Avoid

• Using today's tuition price as the target. The actual cost by the time your child enrolls will almost certainly be higher.
• Assuming an unrealistically high return. Most 529 age-based portfolios grow more conservative as college nears, which lowers the blended return over time.
• Forgetting room, board, and fees. Tuition alone often understates the real annual cost of attendance.
• Not accounting for inflation during the college years themselves. Costs keep rising in year two, three, and four, not just up to enrollment.
• Ignoring your state's 529 tax deduction. Skipping your own state's plan can mean leaving free money on the table.
• Assuming a shortfall means you failed. Financial aid, scholarships, and the new Roth rollover option all reduce the real-world risk of a gap.

Related Free Tools From Arb Digital

Once you've projected your 529 balance, try the Compound Interest Calculator to model different contribution scenarios, the Savings Goal Calculator to work backward from a target date, the Annuity Calculator if you're also planning long-term retirement income, and the Annuity Payout Calculator for the distribution phase. Browse everything in our free online tools hub.

Frequently Asked Questions

This tool provides general estimates for educational purposes only and is not financial, tax, legal, or medical advice. Figures are illustrative; consult a licensed professional for decisions.