Home Affordability SimulatorBuy the house without giving up early retirement

How a house purchase moves your FIRE date

The standard FIRE arithmetic is one line: financial independence arrives when your portfolio reaches your annual spending divided by a safe withdrawal rate — spend $78,000 a year, use 4%, and your number is $1.95 million. Buying a house doesn't just add a line item to that equation; it rewires both sides of it, in opposite directions, on different timelines. That's why intuition fails and the honest answers come from simulation.

Three forces, two directions

Force one: the purchase slows your compounding. The down payment and closing costs leave your portfolio on day one — often six figures, often triggering capital-gains tax on the way out. Every future dollar of property tax, insurance, maintenance, and interest is a dollar that doesn't become shares. Early on, a house is almost purely a drag on the portfolio's growth rate.

Force two: while you owe, your target is higher. Independence means covering your costs from the portfolio — including the house's. A housing-aware threshold, the one this site's model uses, adds ongoing ownership costs and the remaining mortgage balance to your number while they exist. Home equity doesn't count toward it, because you can't spend the house you live in.

Force three: a paid-down house permanently shrinks the target. A renter needs their portfolio to cover rent that grows every year, forever. An owner's threshold falls as the mortgage amortizes; once it's gone, the portfolio only has to cover taxes, insurance, and upkeep. For a house rented at $2,900 a month, that swap can cut the required portfolio by several hundred thousand dollars — the quiet, structural argument for owning that monthly-payment comparisons miss entirely.

So the FIRE date bends, then (sometimes) snaps back

Put the three forces together and the typical trajectory makes sense: buying pushes the median independence date later in the early years — the portfolio took a hit and the target went up — and then claws back ground as the balance amortizes and rent inflation compounds in the counterfactual. Whether it nets out ahead of renting by your target age depends on the inputs you'd expect: price relative to income, your savings rate, rent levels in your market, mortgage rate, and how much house you bought relative to what you could have. The price is the lever you control. Small changes matter more than people expect, because price moves all three forces at once — a cheaper house is simultaneously a smaller portfolio hit, a lower threshold while owing, and a faster path to the paid-off state.

Odds, not dates

A single projected FIRE date is false precision — market sequence, home-price paths, and layoff timing spread the honest answer across a decade. The useful summary is a probability: at this price, what share of simulated futures reach independence by your target age? Grade prices by that number (this site calls ≥85% comfortable, 70–85% workable) and the affordability question becomes concrete. You can see the whole curve — odds as a function of price — in the planner, prefilled for combinations like a $650K house on a $200K salary, with every assumption yours to change. If the odds at your dream price come back low, the fix is rarely mysterious: less house, more years, or less spending. The simulation just tells you how much of which.

Read next