Federal + methodology
Retirement Planning Calculators
Withdrawal-rate sustainability (Bengen + Trinity), required minimum distributions, backdoor Roth conversions, Solo 401(k) limits, FBAR penalties, and the cross-state tax mechanics retirees actually face.
7 calculators cover this topic
IRC § 401(a)(9) (Required Minimum Distribution requirement for qualified plans)
Federal Required Minimum Distribution (RMD) Calculator
Compute the IRC § 401(a)(9) Required Minimum Distribution for traditional retirement accounts (Traditional IRA, 401(k), 403(b), 457(b), TSP, SIMPLE IRA, SEP-IRA) under the SECURE Act 1.0 + SECURE Act 2.0 framework. Models the birth-year cohort RBD lookup (age 70½ for born ≤1950, age 73 for 1951-1959, age 75 for 1960+), the Uniform Lifetime Table divisor lookup, the Joint Life Table for spouses more than 10 years younger as sole beneficiary, the § 4974 excise tax on missed RMD (25% standard, 10% if corrected within the two-year window under SECURE 2.0), the first-year RBD April 1 grace deadline, and the Roth IRA exemption during owner's lifetime under § 408A(c)(5). Federal-pure mechanics for any jurisdiction.
IRC § 911 (full section
Federal Foreign Earned Income Exclusion (FEIE / § 911) Calculator
Compute the IRC § 911 Foreign Earned Income Exclusion (FEIE) for American expatriates, digital nomads, and self-employed taxpayers working abroad. Models the 2026 inflation-indexed FEIE limit ($133,500), the two qualifying tests under § 911(d)(1) (Bona Fide Residence Test and the strict 330-full-day Physical Presence Test), the foreign housing exclusion/deduction under § 911(c) (16% base, 30% standard cap, high-cost-locality multiplier for London/Tokyo/Singapore/etc.), the W-2-employee-exclusion vs self-employed-deduction split, the § 911(f) stack-up effect on remaining taxable income, and the practical FEIE-vs-Foreign-Tax-Credit (§ 901) tradeoff. Surfaces eligibility, FEIE limit lookup, earned-income exclusion, housing exclusion, total excluded, taxable foreign income remaining, daily-equivalent prorate, Form 2555 requirement, and stack-up bracket caveat in a single planning view.
IRC § 223 (Health Savings Accounts — establishment
Federal HSA Contribution & Tax Benefit Calculator
Compute the IRC § 223 Health Savings Account maximum contribution and triple-tax-advantage benefit for the 2026 tax year. Models the self-only ($4,400 est.) and family ($8,750 est.) contribution limits, the age-55+ catch-up ($1,000 statutory under § 223(b)(3)), the immediate federal + state + FICA tax savings (FICA layer only via Section 125 payroll), the § 4973(g) 6% excise tax on excess contributions, the § 223(f)(4) 20% additional tax on non-qualified withdrawals before age 65, and the long-horizon tax-free growth projection under § 223(e)(1). Federal-pure mechanics — HDHP eligibility under § 223(c)(2) (2026 estimated: $1,700 / $3,400 minimum deductible, $8,500 / $17,000 maximum OOP).
IRC § 408A (Roth IRAs — definition
Federal Backdoor Roth Conversion Calculator
Compute the IRC § 408A Backdoor Roth conversion mechanic for the 2026 tax year, surfacing the most-missed pitfall: the § 408(d)(2) pro-rata aggregation rule. Models the Roth IRA MAGI income-limit phaseouts under § 408A(c)(3) (Single/HoH $150K-$165K est., MFJ $236K-$246K est., MFS $0-$10K), the § 219(b) annual contribution limit ($7,500 est. + $1,000 age-50+ catch-up), the pro-rata calculation across all Traditional/SEP/SIMPLE IRA balances (the trap that turns a tax-free conversion into a meaningful tax bill), the cleanout strategy (rollover pretax IRA balance into a 401(k) — which is NOT aggregated under § 408(d)(2)), the mega backdoor Roth path under § 401(a) using after-tax 401(k) contributions and in-plan Roth conversions, and Form 8606 reporting requirements. Federal-pure mechanics — high-earner workaround for taxpayers excluded from direct Roth contribution by the § 408A(c)(3) income limits.
IRC § 401(k) (Cash or Deferred Arrangements — the master qualified-plan rule that creates the elective deferral mechanic)
Federal Solo 401(k) Contribution Calculator
Compute the IRC § 401(k) Solo 401(k) (Individual 401(k)) maximum contribution for the 2026 tax year across the employee elective deferral bucket (§ 402(g), $23,500 est.) and the employer profit-sharing bucket (§ 404(a)(3), 25% of compensation), subject to the § 415(c) annual additions limit ($73,500 est.) and the § 401(a)(17) compensation cap ($355,000 est.). Models the sole-prop circular math (effective 20% rate after half-SE adjustment per IRS Pub. 560), the S-corp 25% rate on W-2 wages, the § 414(v) age 50+ catch-up ($7,500), and the SECURE Act 2.0 § 109 age 60-63 super catch-up ($11,250). Federal-pure mechanics — Solo 401(k) status requires no W-2 employees other than the owner and spouse.
IRC § 125 (Cafeteria Plans — umbrella for pretax health and dependent care benefits)
Federal Health & Dependent Care FSA Calculator
Compute the IRC § 125 Health FSA (2026 estimated $3,500 limit) and IRC § 129 Dependent Care FSA (statutory $5,000 / $2,500 MFS) contribution and tax-benefit. Models the use-it-or-lose-it rule under Treas. Reg. § 1.125-5, the employer-elected $680 (2026 est.) carryover under Notice 2013-71, the alternative 2.5-month grace period under Notice 2005-42 (mutually exclusive with carryover), the forfeiture risk net of safety valves, the immediate federal + state + FICA tax savings (7.65% FICA always available via § 125 payroll), the W-2 inclusion treatment of excess elections, and the structural tradeoffs vs IRC § 223 HSA. Federal-pure mechanics.