Your household
A married couple filing jointly. Change anything; both futures re-run instantly.
What she can actually live on
Not the tax bill — the standard of living. The tool solves the spending level each future can sustain to the end of the plan (in today's dollars, ignoring the survivor-% input, which only drives the sections below), then splits her drop into the part nobody can plan away and the part the tax system takes.
The year after
The first full year alone, against the same year had both lived. The honest comparison is tax per dollar of spending — the survivor's income drops too, but the tax drops far less.
Federal tax, year by year
Two futures for the same household. The gap that opens at the marker is the widow's penalty, compounding for the rest of the plan.
Year-by-year table (survivor path) — show your work
How the math works
What "sustainable" means
The headline section ignores the spending you typed in and instead solves for it: the largest inflation-adjusted spending level each future can carry to the end of the plan without running out. For the comparison, the couple is assumed to spend at their own sustainable maximum until the death — a level playing field, so the drop measures the futures, not the inputs. The decomposition comes from a counterfactual run in which she keeps the survivor benefit but is taxed as if still married: the gap between that world and hers is the widow's penalty with everything else held equal, expressed in dollars of annual living rather than dollars of tax.
What changes in the death year
From the chosen age on: filing status flips from married-joint to single — bracket edges at roughly half the income, and the standard deduction drops from $32,200 + $3,300 to $16,100 + $2,050 (2026 figures, indexed by your inflation number) — household Social Security drops to the survivor benefit you set, and spending drops to the survivor's level. What does not change: the traditional IRA and its RMDs. A surviving spouse who rolls the account into their own name takes the same-sized forced distributions through single brackets that were sized for two.
The three-way squeeze
The penalty compounds through three channels at once. The bracket squeeze: the same real income now climbs a bracket ladder with half-width rungs. The deduction cut: about $17,000 of income that was free now isn't. And the Social Security squeeze: the single filer's provisional-income thresholds ($25,000/$34,000) are far lower than the joint ones, so a larger share of a smaller benefit becomes taxable. The snapshot table shows all three.
What a couple can do about it, while they're both alive
This tool doesn't give advice, but it makes one fact visible: the married-filing-jointly years are the cheapest years this household will ever have for moving money out of the traditional account. Roth conversions done at joint rates are insurance against single rates later — that's the connection to the Roth conversion tool, which prices exactly that move. The other lever is the withdrawal order while both are alive; switch it above and watch the penalty change.
What this tool is not
Both spouses are modeled at the same age, and the survivor benefit is a number you enter, not a computed one (the real rules — survivor takes the larger benefit, with adjustments for claiming age — have their own machinery). Pension survivorship elections aren't modeled; if your pension halves at death, fold that into the survivor inputs. Not modeled: state tax and state estate tax, IRMAA (the survivor's single thresholds make this worse in reality), NIIT, the qualifying-surviving-spouse filing status (available for two years when a dependent child lives at home — rare in retirement), the medical-expense deductions common in a final year, and the step-up in basis the survivor typically gets on jointly held taxable assets, which softens the taxable-account side of the picture. The federal mechanics shown — brackets, deduction, Social Security, RMDs — are the dominant effect.