529 calculator: what the account reaches, what your state gives back, and what a brokerage account would leave
Three answers from one set of inputs: the balance at the first tuition bill, the yearly state break, and the same money taxed in a regular account.
In the 529 at age 18
$110,759
$9,339 more than the same money in a taxable account, plus $3,353 of Georgia tax saved along the way.
| You put in | $67,200 |
| Growth, tax-free for school costs | $43,559 |
| Taxable account after tax | $101,420 |
| Georgia tax saved, 16 years | $3,353 |
Taxable account: dividends taxed every year and the remaining gain taxed at sale, at the 2026 federal capital gains rate for this income, NIIT where it applies, and your state marginal rate.
| Year | Child’s age | Put in | 529 balance |
|---|---|---|---|
| 3 | 5 | $12,600 | $13,735 |
| 6 | 8 | $25,200 | $30,094 |
| 9 | 11 | $37,800 | $49,577 |
| 12 | 14 | $50,400 | $72,782 |
| 15 | 17 | $63,000 | $100,419 |
| 16 | 18 | $67,200 | $110,759 |
Worked out by Radif Partners · How we calculate · federal rules from Public Law 119-21 and IRS Publication 970, state rules from each state · not tax advice
Enter your child's age, a monthly deposit, your state and your taxable income, and the calculator gives three figures for 2026 rules. First, the 529 balance when the first tuition bill arrives, compounded monthly at a return you choose (6 % by default, an assumption and never a forecast). Second, the state income tax your deposits save each year, computed with your own state's brackets and cap rather than a top rate. Third, what the same deposits would be worth after tax in a taxable brokerage account, where dividends are taxed every year and the remaining gain is taxed at sale at the 2026 federal capital gains rate for your income, plus the 3.8 % net investment income tax where it applies and your state rate. A Georgia couple at $145,000 putting $350 a month in from age 2 ends near $110,759, $9,339 more than the taxable account, plus $3,353 of Georgia tax saved along the way.
Three numbers, one set of inputs
Most pages that call themselves a 529 calculator either have no calculator at all, or they fix the household for you: one income, one state, often the highest marginal rate in the country. The figure that comes out is then right for almost nobody. The tool above asks for the few facts that move the answer: how old the child is today, what goes in each month, what is already saved, the state you file in, filing status and taxable income. Everything else sits in the folded settings with a visible default.
The headline is the balance at the age of the first bill (18 by default, changeable). Under it, the line about the taxable account and the state saving gives the two comparisons that a balance alone hides. The year-by-year table shows how much of the balance is your own money and how much is growth, which matters later: only the growth part is ever taxed, and only if the money is not spent on school.
The assumptions, stated plainly
Return. The yearly return is a single nominal rate applied every month, 6 % unless you change it. Real markets move in jumps and drops; a fixed rate gives a smooth path that is useful for comparing choices, not for predicting a balance. The table below runs the Georgia couple at three rates so the spread is visible.
| Assumed yearly return | 529 at 18 | Taxable account after tax | 529 ahead by |
|---|---|---|---|
| 4 % | $93,332 | $87,747 | $5,585 |
| 6 % | $110,759 | $101,420 | $9,339 |
| 8 % | $131,967 | $118,038 | $13,929 |
Deposits. Money goes in at the end of each month and nothing is withdrawn before the first bill. A lump already saved compounds from day one. Fees are not modeled separately: if your plan charges an expense ratio, lower the return by that amount.
The taxable account. It holds the same investments and receives the same deposits. Each year it pays tax on a dividend yield (1.5 % by default) at the federal long-term rate for your income, plus the net investment income tax (NIIT) above $200,000 single or $250,000 joint, plus your state's marginal rate. At the end it is sold and the gain above your cost basis is taxed at the same combined rate. For the Georgia couple that rate is 15 % federal plus 4.99 % state.
The 529. Withdrawals for qualified education costs leave the account with no federal tax on the growth (26 U.S.C. 529). The calculator assumes every dollar is spent that way. The non-qualified withdrawal page covers what happens to the dollars that are not.
How the state break adds up
No federal deduction exists for a 529 deposit. The break, where there is one, comes from your state return, and it is recomputed each year: deposit times your state's rule, capped, at your bracket. The calculator applies the rule of the state you pick to twelve months of deposits and multiplies by the number of saving years. It does not reinvest the refund; if you put each year's saving back into the account, it would itself grow.
For the Georgia couple, $4,200 a year subtracted at 4.99 % returns $210 each spring, or $3,353 over 16 years. Fed back into the 529 at the same assumed 6 %, those refunds would add about $5,527 at 18. The same deposit is worth very different amounts across the border:
| State | Rule | Saved on this year’s deposit | Per $1,000 |
|---|---|---|---|
| Georgia | Deduction | $210 | $50 |
| Arizona | Deduction | $100 | $24 |
| Illinois | Deduction | $208 | $49 |
| Virginia | Deduction | $230 | $55 |
| Indiana | Credit | $840 | $200 |
| Mississippi | Deduction | $168 | $40 |
| Texas | No income tax | $0 | $0 |
Your yearly deposit against your state rule
Georgia tax saved on this contribution
$210
| Subtracted from state income | $4,200 |
| Your state marginal rate | 4.99 % |
| Cap that applies this year | $8,000 |
| Back per $1,000 contributed | $50 |
13 of the 51 jurisdictions in our table give nothing back on a deposit, either because they have no wage income tax or because they offer no 529 deduction or credit. For a household there, the calculator's state line reads zero and the comparison rests on federal tax alone. A Texas couple at $180,000 saving $500 a month from age 4 still ends $7,281 ahead of the taxable account, because the dividends and the final gain escape federal tax.
Reading the result for a smaller budget
An Arizona single parent at $68,000 who starts at $200 a month when the child turns 6 has twelve years of compounding, not sixteen. The balance lands near $41,590, of which $28,800 is deposits. The taxable account would leave $39,230, so the 529 edge is $2,359, and Arizona's subtraction, which accepts any state's plan, returns $50 a year, because only the first $2,000 per child counts on a single return. Shorter horizons shrink the federal advantage faster than the state one: the state break arrives in year one, while tax-free growth needs time to build.
Same Arizona saver, another return
In the 529 at age 18
$41,590
| You put in | $28,800 |
| Growth, tax-free for school costs | $12,790 |
| Taxable account after tax | $39,230 |
| Arizona tax saved, 12 years | $600 |
What the figure does not include
The balance is in future dollars. College costs will also have moved by then, so a target set in today's prices needs the monthly saving calculator, which carries a cost forward at a rate you choose. The result ignores financial aid, scholarships and education credits; the credits page explains why the same dollar cannot be both a tax-free withdrawal and a credit expense. It also leaves aside state add-backs if money later moves to another state's plan or goes to a use your state does not accept. A full head-to-head on flexibility, with the 10 % additional tax on unused earnings, is on the 529 against a taxable account page.