David, 52 — California

The data shows the household crossing financial independence around age 58 — before the age-60 goal. The line it has to cross is set by spending: at $7,500/month, the plan needs $2,527,397 to sustain itself.

Because the answer is computed, not asserted, it moves when the inputs do — retire a year earlier, spend $500 more a month, and the chart recomputes the crossing on the spot. That is what “knowing your runway” means at 52: not a promise, a live calculation you can interrogate.

The engine computes the married-filing-jointly stack from the actual rules: gross $300,000 → a $24,500 pre-tax 401(k) deferral → the $32,200 MFJ standard deduction → federal taxable income of $243,300. Federal tax $43,588, FICA $16,239, California $18,706 — total $78,533, leaving $221,467 post-tax (26.2% effective).

One modeling note, stated because honesty is the product: the engine currently runs household income through a single earner. That caps the 401(k) deferral at one worker’s federal limit — understating the household’s tax benefit — and applies one Social Security wage base, so a couple with two W-2s can owe more Social Security tax than a single earner with the same combined income. The stack above is exact for a one-W-2 household; for a two-W-2 split, the FICA line reads low. The pre-tax deferral is why the taxable number is smaller than the gross — the math is visible, not hidden behind a summary.

The plan computes a 57% savings rate from real cash flows — take-home $18,456/mo against $7,500/mo of spending plus $2,708/mo of 401(k) contributions. At 52, that rate acts on a portfolio that already exists, which is why the FI crossing sits where it does rather than decades away.

The verdict line on the household briefing reads: “Financial Independence at ≈58 — the day work becomes optional” — recomputed on every input change, never cached.