Custodial Roth IRA Calculator
Once a child earns income, a custodial Roth IRA gives them the one thing no adult can buy back: time. See how modest contributions during the teen and college years, capped at what the child earns, can compound tax-free into a large retirement balance decades later.
Educational estimate, not tax or investment advice. Contributions require the child to have earned income; returns are never guaranteed.
A custodial Roth needs the child to have earned income; many start once a teen takes a summer job.
What you plan to add each year. Capped at the child's earnings and the annual limit below.
Wages or self-employment income the child earns. Contributions cannot exceed this.
Many families fund it through the teen and college years, then let it grow on its own.
A moderate long-run assumption for a diversified portfolio. Returns are never guaranteed.
Roth withdrawals are qualified from age 59 and a half, so retirement is the natural horizon.
Tax-free balance at age 60
$245,276
From $12,000 contributed over 6 years, a 20.4x return, all withdrawable tax-free in retirement.
- Contributed each year
- $2,000
- Total contributed
- $12,000
- Balance when contributions stop (age 18)
- $14,307
- Tax-free growth
- $233,276
A Roth is funded with after-tax dollars, so qualified withdrawals in retirement are tax-free. How we calculate this
Next step
A Roth is for retirement. For college savings, our 529 vs UTMA Comparator → weighs the two accounts built for that goal.
Educational estimate, not tax or investment advice. A custodial Roth requires the child to have earned income, and returns are never guaranteed. Figures reviewed July 2026.
Custodial Roth IRA: Your Estimate
Balance at age 60
$245,276
tax-free in retirement
Total contributed
$12,000
Tax-free growth
$233,276
| Your inputs | Value |
|---|---|
| Child’s age now | 12 |
| Yearly contribution (planned) | $2,000 |
| Child’s earned income | $4,000 |
| Contribute until age | 18 |
| Assumed annual return | 7% |
Method & sources
Each year the contribution (capped at the child’s earned income and the $7500 annual limit) is added at year-end and grows at the assumed return, a future-value-of-an-annuity through the contribution years, then plain compounding to the projection age.
- IRS Notice 2025-67: 2026 IRA contribution limit ($7,500); contributions are capped at the child's earned income
- IRS Publication 590-A: contributions to IRAs (earned-income requirement, Roth rules)
- Figures last reviewed July 2026.
Educational estimate only. Not tax or investment advice. A custodial Roth IRA requires the child to have earned income, and contributions are capped at the lesser of that income and the annual IRA limit. Projections use a constant assumed return; real market returns vary. Confirm rules with IRS Publication 590-A or a tax professional.
harborplain.com/tools/custodial-roth-ira-calculator · Printed today · HarborPlain
How we calculate this
The calculator runs two phases. During the contribution years, it adds your yearly amount, capped, at the end of each year and grows the balance at the assumed return (a future-value-of-an-annuity). After contributions stop, the balance compounds untouched to the projection age. The only regulatory number is the contribution limit, from IRS Notice 2025-67; everything else is your input.
The earned-income cap. A child can contribute only up to the lesser of their earned income and the annual limit ($7,500 for 2026). The tool applies both caps, so a bigger planned amount is trimmed to whatever the child can actually contribute. The cash itself can be gifted by a parent or grandparent; what matters is that the child earned at least that much (IRS Publication 590-A).
Why the growth dwarfs the contributions. A Roth is funded with after-tax dollars and grows tax-free, and a child has the longest runway of anyone. Over a full career, the tax-free growth commonly runs to ten times the amount contributed or more, which is the gap the result highlights. Returns are not guaranteed, so treat the figure as an illustration, not a promise. Figures last reviewed July 2026.
How to use the result
Set the child’s current age and what they realistically earn, then a contribution you could sustain (even a few hundred dollars a year compounds). Choose how long to contribute, often through the teen and college years, and a projection age at or beyond 59 and a half, when Roth withdrawals are qualified. If the planned amount shows as capped, the child’s earnings or the annual limit is the binding constraint.
A Roth is the retirement piece of a child’s finances. The college piece is separate: our 529 vs UTMA Comparator weighs the two education-focused accounts, and the College Savings Goal Calculator sizes the monthly saving a tuition target needs.
Frequently asked questions
Yes, at any age, as long as the child has earned income for the year, such as wages from a job or self-employment income from something like babysitting or yard work. An adult opens and manages a custodial Roth IRA on the child's behalf, and control transfers to the child at the age of majority in your state. Allowance and gift money do not count; the contribution must be backed by earnings the child actually made.
Up to the lesser of the child's earned income for the year and the annual IRA limit, which is $7,500 for 2026 (IRS Notice 2025-67). So a teen who earns $4,000 can contribute up to $4,000, while one who earns $9,000 is capped at the $7,500 limit. The money does not have to come from the child's own paycheck; a parent or grandparent can gift the cash to contribute, as long as the child's earnings for the year are at least the amount contributed.
Time. A Roth is funded with after-tax dollars and grows completely tax-free, so decades of compounding turn small early contributions into a large, tax-free retirement balance. A child has the longest possible runway, which is exactly what compounding rewards. The gap between what is contributed and the final balance in the calculator, often ten times or more over a full career, is the tax-free growth doing the work.
Roth contributions (the amounts put in, not the earnings) can generally be withdrawn at any time without tax or penalty, which gives some flexibility. Earnings withdrawn before age 59 and a half and before the account is five years old can face taxes and a penalty, with some exceptions, such as up to $10,000 toward a first home. The projection here assumes the money stays invested to the projection age, which is where the tax-free growth is greatest.
Purpose and taxes. A 529 is for education and grows tax-free only for qualified education costs; an UTMA is a flexible taxable account the child controls at majority. A custodial Roth is for retirement, and its growth is tax-free for that purpose. They are complementary: many families use a 529 for college and a Roth to give a working teen a head start on retirement. Our 529 vs UTMA comparator covers the two education-focused accounts.
No. The calculator runs entirely in your browser and stores nothing on our servers. There is no email box and no sign-up. Your inputs are only reflected in the page's web address so you can bookmark, share, or print your result; clear the link and they are gone.
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Read guide →Educational estimate only. Not tax, legal, or investment advice. A custodial Roth IRA requires the child to have earned income, contributions are capped at the lesser of that income and the annual IRA limit, and the projection assumes a constant return that real markets will not match year to year. Confirm the rules with IRS Publication 590-A or a qualified tax professional before contributing. HarborPlain explains the math; the decisions are yours.