#tax-strategy

We ran a $15,000 custodial brokerage account through the kiddie tax calculator for high-bracket parents — $12,300 of it gets taxed at the parent's marginal rate, not the child's, once unearned income clears the $2,700 threshold.

We ran $200,000 of qualified business income through the calculator at $428,600 taxable income (MFJ) — $34,000 into the 2025 phase-in range. The W-2 wage limitation already cuts a non-SSTB business's deduction from $40,000 to $36,600.

We ran a textbook $7,000 backdoor Roth contribution through the calculator against a $93,000 old 401(k) rollover IRA sitting in the background — the pro-rata rule taxes 93% of the conversion, even though the new contribution itself was done correctly.