How to use this calculator
- Enter your child's age on December 31 this year and how many years of college to plan for.
- Choose the kind of college, or My own amount to enter one school's yearly cost. Use the costs a 529 can pay: tuition, fees, housing, food and books.
- Set the share of the cost you want to cover from savings. The rest might come from income at the time, the student's own work, or loans.
- Enter what you have already saved for this child and the yearly return you expect.
- Read the monthly amount, or the lump sum today. Open "Which account" to compare where to keep the money, and "Show each account" for what each is worth if it goes unused and how it counts for aid.
Under More options you can change the age college starts, keep saving through college, change how much the monthly amount rises each year (2.5% by default), add grants or scholarships you expect, see what a monthly amount you can afford would cover, enter your tax rates for the account comparison, and show the year table in today's dollars. The numbers already filled in are an example. Replace them with your own.
How it's calculated
1. Each college year's cost
Each year's cost today grows at the cost growth rate until the year it is paid. In the example, $27,180 a year at a public in-state college today, growing 3.9% a year, is $48,248 in 2041, when your child turns 18, and $54,116 in 2044. Grants and scholarships you expect grow at the same rate and come off first; then the share you choose to cover is applied. Four years come to $204,580, which is $108,720 at today's prices.
2. How the savings grow
Each month's saving goes in at the month's end. The balance earns the yearly return once a year, and money added during the year earns simple interest for the part of the year it was invested, so a year of saving D a month adds D × (12 + 5.5 × the return) by the year's end. The monthly amount rises once a year. Each college year is paid in one payment at its start, and what is left stays invested. In the example, the first year's $436 a month and the $10,000 already saved grow to $16,100 by the end of the year.
3. The monthly amount and the lump sum
The monthly amount is the smallest whole-dollar amount that pays every college year in full: the example needs $436 a month this year, rising 2.5% a year, or a level $506 a month; a dollar less falls short. Saving through college instead of stopping when it starts brings it to $385. The lump sum is the smallest whole-dollar amount put in today, on top of what you have saved, that does the same: $56,969. For a newborn with nothing saved yet, the same college takes $414 a month to start.
Other college calculators can give a figure 10% or more higher or lower for the same family, and the cause is usually timing rather than a mistake. Saving through college, depositing at the start of each month, or paying each year at its end all lower the monthly amount; aiming to have the whole cost in hand on the first day of college, or depositing once a year, raises it. A fixed 5% cost growth raises it further. This page says which it uses: money invested until each year is paid, deposits at each month's end, and saving that stops when college starts unless you choose otherwise.
4. The account comparison
Each account gets the same monthly savings and the same return, and each college year withdraws enough to pay that year's amount after the federal tax the withdrawal owes. A 529 plan owes none on qualified expenses. A taxable account pays your capital gains rate on the gain in each withdrawal. A custodial account is the child's: its gains are taxed under the kiddie tax, nothing on the first $2,700 a year and your rate above that, and from the year the child turns 24 at the child's own rates. A Roth IRA takes up to one parent's yearly limit, with the rest in a taxable account; contributions come out first and tax-free, then the taxable account, then the earnings, taxed at your bracket. A Trump account takes up to $5,000 a year until the year the child turns 18, with the rest in a taxable account; the taxable account pays first, then the Trump account, whose growth is the child's income. Withdrawals from either IRA above the year's qualified expenses also owe the 10% additional tax. In the example, the 529 covers all of it, the custodial account 92.9%, the taxable account 92.0%, the Trump account 89.9% and the Roth IRA 89.6%.
5. If the money is never used, and financial aid
"If not used" cashes each account out when college would start, after federal tax: a 529's earnings pay your bracket plus the 10% additional tax, a taxable account's gain pays your capital gains rate, and a Roth IRA's earnings pay your bracket plus 10%. "Aid, up to" adds, for each college year, 5.64% of the parent's countable accounts and 20% of the child's, which are the most the Student Aid Index formula can assess, plus 47% of the parent's and 50% of the child's income from withdrawals that a later FAFSA will see. In the example, the 529 could add at most $27,529 over four years, the custodial account $117,188.
6. Rounding
Every amount is worked out to the cent at the step that produces it, and each year's tax is rounded once. Growth rates are applied exactly, not with rounded multipliers. The page shows whole dollars.
Assumptions and limits
- One return every year, including the college years. Many 529 plans offer age-based portfolios that move toward bonds and cash as college nears, which lowers the expected return in those years.
- College costs grow at one rate for every year and every kind of cost. The two-year and out-of-state presets use the four-year colleges' growth rate, because the College Board publishes no comparable series for them.
- The presets count tuition, fees, the school's housing and food allowance and its books allowance. A 529 pays housing only for a student enrolled at least half-time, up to the school's allowance, and only for costs the student actually pays, so a student living at home rent-free has less to cover. Transportation and personal spending are not qualified and are left out.
- In the account comparison, your tax rates stay as they are, and this year's figures (the IRA limit, the kiddie-tax amount, the child's own brackets) stay at this year's level, though they rise with inflation; that understates the room in the custodial, Roth IRA and Trump rows. Dividends taxed along the way would lower the taxable and custodial rows. What you have saved goes into each account as new money. The child has no other income and, through age 23, is a student who earns less than half their support. The Roth IRA belongs to one parent under 59½, with no catch-up contribution. The Trump account leaves out the federal $1,000 deposit and employer contributions. The order of withdrawals within the Roth IRA and Trump rows is a choice this calculator makes.
- The financial aid figure is the most each account could add to the Student Aid Index over the college years, before the allowances that reduce it. It can be $0 for a family that does not have to report assets. Colleges that use the CSS Profile count some accounts differently.
- Federal tax only: no state deduction or credit for 529 contributions, and no state tax on withdrawals. Check your state's plan, because a state deduction can be a reason to choose it. If you claim the American Opportunity credit, the expenses it counts (up to $4,000 a year) must be paid with money other than tax-free 529 withdrawals.
- It does not cover K-12 tuition, graduate school, more than one child, prepaid tuition plans, Coverdell accounts, a second parent's Roth IRA, or estimates of aid from your income.
Input field details
What to enter in each box, where to find the number, and how this calculator treats it. When two calculators give different answers from the same numbers, it's usually because they handle one of these differently.
Child’s age
Your child’s age on December 31 this year.
How this tool treats itAges count by calendar year: your child is a year older at the end of each later year. The tax rules for a custodial account and a Trump account turn on these ages.
Allowed range0 to 17
Years of college
How many years of college to pay for. Enter 2 for a two-year college.
How this tool treats itEach year is paid in one payment at its start, and the money not yet needed stays invested.
Allowed range1 to 6
Not includedGraduate school.
Kind of college
The kind of college you are saving for, or My own amount to enter a yearly cost yourself.
Where to find itThe College Board’s average 2025-26 published prices for full-time undergraduates: public four-year, in-state $27,180 (tuition and fees $11,950, housing and food $13,900, books and supplies $1,330); public four-year, out-of-state $47,110; private nonprofit four-year $62,260; public two-year, in-district $16,570, the budget for a student who commutes. Source: Ma, Jennifer, Matea Pender, and Xiaowen Hu (2025). Trends in College Pricing and Student Aid 2025, New York: College Board.
How this tool treats itEach preset counts tuition and fees, housing and food, and books and supplies, the costs a 529 can pay tax-free. A 529 pays housing and food only for a student enrolled at least half-time, up to the college’s allowance, and only for costs the student pays, so a student living at home rent-free has none. The books figure is a budget allowance, not a measured spend. Transportation and personal spending are left out: a 529 cannot pay them tax-free.
Not includedGraduate school and K-12 tuition.
Yearly cost today
One year’s cost at your child’s college in today’s prices: tuition, fees, housing, food and books.
Where to find itThe cost of attendance the college publishes on its financial aid pages.
How this tool treats itUsed only with My own amount. It grows each year at the college cost growth rate. Leave out transportation and personal spending: a 529 cannot pay them tax-free.
Allowed range$100 to $250,000 a year
College cost growth a year
How fast you expect college costs to rise each year.
Where to find itPublished tuition, fees, housing and food in current dollars rose 3.86% a year at public four-year colleges and 3.83% at private nonprofit four-year colleges from 2005-06 to 2025-26; 2.82% and 3.34% from 2015-16; and 4.58% and 4.27% from 1995-96 (College Board, Trends in College Pricing and Student Aid 2025, Table CP-2). The default, 3.9%, is the 20-year rate.
How this tool treats itOne rate for every year and every kind of cost. The College Board publishes no series of this kind for two-year or out-of-state prices, so those presets use the same default. Grants and scholarships grow at this rate too.
Allowed range0% to 10%, in steps of 0.1%
Saved so far
What you have already set aside for this child’s college.
Where to find itYour latest 529 plan or account statement.
How this tool treats itInvested from today at the yearly return. In the account comparison it goes into each account as new money.
Allowed range$0 to $5,000,000
Yearly return
The average yearly return you expect on the savings, before any fees.
How this tool treats itThe same return every year, college years included, credited once a year. Each month’s saving goes in at the month’s end and earns simple interest for the rest of that year. Many 529 plans offer age-based portfolios that move toward bonds and cash as college nears, which lowers the expected return in those years. Returns are an assumption, not a forecast. Over the long run the S&P 500 returned about 10.2% a year nominally (January 1926 to September 2023, computed from Robert Shiller's series, dividends reinvested, before taxes, fees and any advisor cost), while consumer prices rose about 3.0% a year (1926 to 2024, computed from the CPI-U). Neither is what any single decade delivered, and a real portfolio is not an index: you cannot invest directly in one. Every figure this tool produces is a hypothetical illustration of the assumptions you entered.
Allowed range0% to 20%, in steps of 0.1%
Not includedReturns that vary from year to year, and fees.
Age they start college
The age your child will be at the end of the calendar year college starts.
How this tool treats itAn age below your child’s age today is read as this year.
Allowed range14 to 25
Keep saving through college
Turn on to keep saving every month while your child is in college.
How this tool treats itOn, saving continues until the last year’s payment, and each college year is paid before that year’s saving. Off, saving stops when college starts.
Raise the monthly amount each year by
How much you plan to raise the monthly amount each year. 0% keeps it level.
How this tool treats itThe answer is the first year’s monthly amount; each later year’s is that amount raised by this rate once a year, rounded to the cent. 2.5% unless you change it.
Allowed range0% to 10%, in steps of 0.5%
Grants and scholarships a year
The grants and scholarships you expect each year, in today’s dollars.
How this tool treats itThey grow with college costs and come off each year’s cost before the share is applied. Tax-free grants also lower what a 529 can pay tax-free and what the education exception to the 10% additional tax on IRA withdrawals covers.
Allowed range$0 to $250,000 a year
Not includedEstimating aid from your income, and each college’s own aid policy.
What you can save a month
What you can set aside each month, to see how much of the cost it would pay. Leave it at $0 to skip.
How this tool treats itSaved and raised each year the same way as the answer, from a 529 plan.
Allowed range$0 to $100,000 a month
Your federal income tax bracket
The rate on your top dollars of income: the bracket your taxable income reaches.
Where to find itThe taxable income on your latest Form 1040, against that year’s brackets.
How this tool treats itUsed only in the account comparison, at the same rate every year. Roth IRA earnings withdrawn early, a 529 or Roth IRA cashed out, and a child’s Trump account income above twice the kiddie-tax amount are taxed at this rate.
Not includedState income tax.
Your capital gains rate
The rate on your long-term capital gains: 0%, 15% or 20%, plus the 3.8% net investment income tax if your modified adjusted gross income is above $200,000 ($250,000 married filing jointly).
How this tool treats itUsed only in the account comparison. Gains in a taxable account are taxed at this rate when sold; a child’s gains above twice the kiddie-tax amount are taxed at it without the 3.8%. A 0% rate applies only to taxable income in the 10% and 12% brackets.
Show in today’s dollars
Turn on to show the year-by-year figures in today’s dollars.
How this tool treats itEach figure is divided by 2.5% inflation a year from today: a year-end balance and that year’s growth by the years to the year’s end, a payment or a year’s saving by the years to the year’s start.
Questions
Is a 529 better than a Roth IRA for college?
What happens to 529 money if my child doesn’t go to college?
How does a 529 affect financial aid?
How much can I put in a 529 at once?
What is a Trump account, and does it help with college?
How fast do college costs rise?
Should I use a custodial UTMA or UGMA account instead?
Version history
- October 31, 2026 (version 1.0.0): First version: the monthly amount and lump sum for the share of college you choose, and five ways to hold the same savings compared after federal tax, if the money goes unused, and for financial aid.