Not financial advice — a what-if model to react to, not a plan. Proceeds-only: this treats the net sale proceeds as their own invested pot, not our whole portfolio. Every number below traces back to a labeled cell on the "Downsize Model" sheet tab or is pulled live from the transaction feed — nothing here is hardcoded in the script.
Selling today would net an estimated $745,911 after our mortgage, selling costs, and capital gains tax (live-tracked payoff is currently $387,671, below the $400,000 assumption). Invested, that could sustainably support about $2,550/mo in rent at 90% confidence over 25 years — less than the $3,962/mo it effectively costs to own our house today, after netting out the mortgage-interest and property-tax tax benefit (see below) — costing roughly $1,412/mo.
Monte Carlo, 3,000 trials, real terms (already inflation-adjusted — expected return 5%/yr, volatility 12%/yr). General inflation and rent inflation are both assumed at 3%/yr, so rent is assumed to track general prices exactly — the withdrawal below is a flat real (inflation-adjusted) amount, it does not need to grow on its own. Ruin is permanent — once a path hits zero it stays there. Each column is the largest monthly withdrawal that still succeeds (never runs out) in at least that fraction of the 1,000 simulated paths. 50 years stands in for "indefinitely." Figures below are shown per month; the model itself simulates in annual terms.
| Horizon | 75% confidence /mo | 90% confidence /mo | 95% confidence /mo |
|---|---|---|---|
| 20 | $3,708 | $3,013 | $2,781 |
| 25 | $3,245 | $2,550 | $2,318 |
| 30 | $2,897 | $2,318 | $1,970 |
| 50 (indefinite proxy) | $2,202 | $1,738 | $1,391 |
Not a CPA figure — for CPA review, not a substitute for one. Mortgage interest and property tax are deductible; renting has no comparable deduction. This estimates that benefit and nets it out of the "cost of owning" comparison above, using the illustrative example rates and other-deductions baseline on the "Downsize Model" sheet tab, applied live to whatever mortgage interest and property tax the current 12-month window shows. Two deliberate simplifications, both explained where they apply: the federal side accounts for the standard deduction (see below — it matters, roughly halves the naive number); the California side does not, because it doesn't change the answer enough to be worth the complexity for our household specifically.
| Current market value | $1,250,000 |
| Original purchase price | $480,000 |
| Capital improvements | $95,000 |
| Remaining mortgage balance | $400,000 |
| Transfer tax + closing costs rate | 6.11% |
| Combined cap-gains rate on taxable gain | 28.1% |
| Federal / CA marginal ordinary rate (mortgage & property tax) | 22% / 9.3% |
| Expected real return / volatility | 5% / 12% |
| General inflation | 3.0%/yr |
| Rent inflation | 3.0%/yr |
| → Rent's real growth rate (derived) | +0.0%/yr |
| Cost of owning our house — raw cash / net of tax benefit | $55,431 / $47,541 |
Not a CFP/CPA figure. Cap-gains rate is an illustrative example (15% federal bracket, not the 20% top rate) — check it against your own actual return, since a large enough gain could push into the 20% band. Selling now realizes and taxes the gain today; holding our house until death gives heirs a full step-up in basis instead, which is a real trade-off worth raising with the CFP separately from this model.