Roth Conversion Calculator for Trump Accounts
Model the pro rata rule, kiddie tax (Form 8615), and dependent vs independent Roth conversion math.
Why This Calculator Matters
When a Trump Account becomes a traditional IRA at 18, a Roth conversion can lock in tax-free growth. Only the earnings share is taxable (the pro rata rule). But a typical 18-year-old on parental support does not get the full single standard deduction — and conversion earnings can be kiddie-taxed at the parent’s rate. Toggle the filer type below to see both cases.
Step 1
Trump Account
Ages 0–17
Step 2
Traditional IRA
Converts at 18
Step 3
Roth IRA
Convert strategically
Quick scenarios
Trump Account at Age 18
Money you put in — no tax deduction taken. This is NOT taxed on conversion.
For a supported student, large conversions at 18–23 can be taxed at the parent’s rate.
Wages can raise a dependent’s standard deduction. Conversion income cannot.
Form 8615 taxes net unearned income (conversion earnings above ~$2,700) at this rate.
The Pro Rata Rule
Because your Trump Account contributions were after-tax (no deduction), 60.0% of every dollar converted is a return of your basis and not taxed. Only the 40.0% that is growth is taxable. A typical supported 18-year-old does not get the full single standard deduction. About $3,375 can convert at $0 federal tax, and about $6,750 keeps taxable earnings under the ~$2,700 kiddie-tax threshold.
Kiddie tax applies in 2 years
Taxable conversion earnings above ~$2,700 are taxed at the parent’s 24% rate, not the child’s 10–12% brackets. College years on parental support are often a costly window — not a free one. See the kiddie tax guide.
Total Tax Paid
$8,958
Effective rate: 8.6%
Total Converted to Roth
$104,000
Over 2 years
Roth IRA at 65
$3,723,201
Tax-free withdrawals
Trad. IRA at 65 (net)
$2,904,097
After ~$819,104 est. tax
Estimated lifetime tax savings from Roth conversion
$819,104
Roth: $3,723,201 tax-free vs Traditional: $2,904,097 after tax
This calculator is for educational purposes only and does not constitute tax or financial advice. Supported-student mode uses a simplified Form 8615 model: dependent standard deduction (~$1,350, or earned income + $450) and the parent’s marginal rate on net unearned income above ~$2,700. Thresholds change with inflation. State taxes and FAFSA effects are not included. Consult a qualified tax professional before executing a Roth conversion.
How the Pro Rata Rule Works
Trump Account contributions are made with after-tax dollars — you don't get a tax deduction. This creates nondeductible basis in the account. When you convert to a Roth IRA, the IRS uses the pro rata rule to determine how much of each converted dollar is taxable:
- Basis percentage = Total contributions ÷ Account balance
- Taxable percentage = 1 − Basis percentage
- Each dollar converted = (basis %) tax-free + (taxable %) ordinary income
Example: If you contributed $60,000 and the account grew to $100,000, your basis is 60%. For every $1 you convert, $0.60 is tax-free and $0.40 is taxable. The IRS does not let you cherry-pick which dollars to convert — it must be proportional.
Kiddie Tax vs Independent Filing
The popular “chunk conversions under the $15,000 standard deduction” story only works if the owner is an independent filer — they cannot be claimed as a dependent, and they are not a Form 8615 “child” that year.
A typical supported student is different. Their standard deduction is about $1,350 (or earned income + $450). Taxable conversion earnings above about $2,700 are taxed at the parent’s rate. College years on parental support are often a costly window, not a free one. Waiting until age 24 — or until they provide more than half their support from wages — can be cheaper.
Deep dives: Roth conversion strategy and does the kiddie tax apply?
Related Resources
Disclaimer: This calculator is for educational and illustrative purposes only. It does not constitute tax or financial advice. Actual returns will vary. Consult a qualified tax professional or financial advisor before making investment decisions.
More Calculators & Tools
Trump Account Calculator
Free Trump Account calculator — eligibility + growth to age 18
Eligibility Checker
Does your child qualify for the $1,000 pilot deposit?
Employer Match Calculator
Model up to $2,500/year under §128
Withdrawal Simulator
Tax impact by withdrawal age
Fund Expense Tracker
Compare eligible ETFs and expense ratios
Legacy Calculator
See the value at age 18, 30, and 65
Cost of Waiting Calculator
See how much delay costs your child
Milestone Calculator
When will the account hit $100K or $1M?
Inflation Comparison
Savings account vs Trump Account over time
Grant Eligibility
Check ZIP codes for grants like the Dell pledge