Wealth & retirement · super (composes 3 primitives)
Inheritance impact
Type the inherited assets and your tax position. We chain step-up basis savings, the SECURE-Act 10-year inherited-IRA drawdown timeline, estate-tax recapture if any, and the bracket impact of forced withdrawals.
No profile data yet. Fill your profile to skip data entry on every super calc.
Inputs
Result
Net after-tax inheritance $561,960 — step-up saves $53,550 on taxable, but Traditional IRA costs $103,040 over 10 years.
Plan the 10-yr withdrawal: Spread the $280,000 Traditional IRA strategically: take more in low-income years (sabbatical, layoff, gap year) and less in high-income years. Could save $13,440 of bracket-creep tax.
- 1
Step-up basis on taxable assets
$53,550
$225,000 of decedent's unrealized gain × 23.8% LTCG+NIIT eliminated. Your new basis = $320,000.
- 2
Inherited taxable assets (basis stepped up)
$320,000
Sell anytime — only post-inheritance gains are taxed
- 3
Traditional IRA — 10-year rule
$280,000
Must drain in 10 years. $28,000/yr if even spread.
- 4
Total income tax on Traditional IRA
$89,600
$280,000 × 32% marginal rate
- 5
10-year compression bracket-creep penalty
$13,440
Concentrated 10-yr withdrawals push you into higher brackets vs lifetime drawdown — typically 10-20% extra tax.
- 6
Inherited Roth IRA
$65,000
Drain in 10 years — but tax-free. Hold to year 10 for max compounding.
- 7
Net after-tax inheritance
$561,960
$665,000 gross − $103,040 tax
Assumptions & notes
- SECURE Act (2019) + SECURE 2.0 (2022) require 10-year drain on most non-spouse inherited Traditional IRAs.
- Eligible Designated Beneficiaries (EDBs): spouse, minor child of decedent, disabled, chronically ill, or beneficiary <10 yrs younger than decedent.
- Step-up basis is on the chopping block periodically in tax-policy debates. As of 2026 it remains in effect.
- Inherited Roth IRA also has 10-year rule, but withdrawals stay tax-free if the original 5-yr clock is satisfied.
Multi-scenario comparison
What if — ±20% on one input
| Scenario | Inherited taxable assets (brokerage, real estate) | Headline | Δ vs baseline | Magnitude |
|---|---|---|---|---|
| −20% (cautious) | $256,000 | Net after-tax inheritance $497,960 — step-up saves $38,318 on taxable, but Traditional IRA costs $103,040 over 10 years. | $-15,232 | |
| Baseline | $320,000 | Net after-tax inheritance $561,960 — step-up saves $53,550 on taxable, but Traditional IRA costs $103,040 over 10 years. | 0 | |
| +20% (aggressive) | $384,000 | Net after-tax inheritance $625,960 — step-up saves $68,782 on taxable, but Traditional IRA costs $103,040 over 10 years. | +$15,232 |
Try the input with the highest sensitivity (above). The Δ column shows the dollar swing from a 20% move — that's how much room you have for a counter, raise, or hedge.
Goal seek
Solve for an input value
Pick the input you want to vary and the output you care about. We'll find the input value that gets you to the target. Bisection-based; converges in < 50 iterations.
Monte Carlo simulation
Distribution under input uncertainty (500 trials)
We perturb every numeric input with normal-distributed noise (10–25% sigma depending on input type) and run 500 compute trials. The output is a probability distribution, not a single number — closer to how finance actually works.
Most-leveraged inputs (sensitivity analysis)
Where to focus — what moves the answer most
Each input perturbed ±10%; measured impact on Step-up basis on taxable assets. Higher elasticity = bigger lever.
- 1
Inherited taxable assets (brokerage, real estate)
Elasticity ↑ 1.42× — 10% change in this input increases Step-up basis on taxable assets by 14.2%.
- 2
Decedent's cost basis in those assets
Elasticity ↓ 0.42× — 10% change in this input decreases Step-up basis on taxable assets by 4.2%.
- 3
Inherited Traditional IRA / 401(k)
Elasticity ↕ 0.00× — 10% change in this input affects Step-up basis on taxable assets by 0.0%.
- 4
Inherited Roth IRA
Elasticity ↕ 0.00× — 10% change in this input affects Step-up basis on taxable assets by 0.0%.
ShowMath is the only calc site that surfaces this. Adjust the highest-leverage input first — that's where small moves create big results.
Chain payload (for the 3D constellation)
{
"slug": "inheritance-impact",
"depth": 1,
"primitives": [
"inheritance-calculator",
"step-up-basis-calculator",
"inherited-ira-calculator"
],
"composes": [],
"chain": [
{
"key": "step_up_basis",
"label": "Step-up basis on taxable assets",
"primitive": "step-up-basis-calculator",
"numeric": 53550
},
{
"key": "inherited_taxable",
"label": "Inherited taxable assets (basis stepped up)",
"numeric": 320000
},
{
"key": "trad_ira_rule",
"label": "Traditional IRA — 10-year rule",
"primitive": "inherited-ira-calculator",
"numeric": 280000
},
{
"key": "trad_ira_tax",
"label": "Total income tax on Traditional IRA",
"numeric": 89600
},
{
"key": "bracket_creep",
"label": "10-year compression bracket-creep penalty",
"numeric": 13440
},
{
"key": "roth_ira",
"label": "Inherited Roth IRA",
"numeric": 65000
},
{
"key": "net_after_tax",
"label": "Net after-tax inheritance",
"numeric": 561960
}
]
}The chain explained
Each step above corresponds to a primitive calculator. Click any to see the stand-alone version with its own explainer + sources.
- inheritance calculatorshipping soon
- step up basis calculatorshipping soon
- inherited ira calculatorshipping soon
Chains naturally with
Wealth & retirement
Estate planning master
Gross estate → federal exemption → state estate tax → step-up basis savings → life insurance gap → probate vs trust cost.
Tax
RMD master
Required Minimum Distribution year-by-year × Traditional balance growth × tax bracket impact × bracket-creep year.
Wealth & retirement
Wealth trajectory
Net worth → savings rate → portfolio growth → retirement projection → Coast FIRE age.
Get the new super calcs as they ship
One email per drop. We're chaining the next 6 right now.