A net-worth comparison over your full time horizon — accounting for mortgage, taxes, insurance, maintenance, home appreciation, and the opportunity cost of every dollar invested instead.
This model doesn't just add up payments — it tracks your ending net worth under each path, which is the only apples-to-apples way to compare.
Buying: You pay the down payment and closing costs up front, then a fixed mortgage payment plus property tax, insurance, maintenance, and any HOA each month. Your home appreciates at the rate you set, and your equity grows as the loan amortizes. At the end of the horizon the home is "sold" — selling costs and the remaining loan balance are subtracted to give your net proceeds.
Renting: You skip the down payment and closing costs, so that money is invested from day one at your assumed return. Rent rises each year. Whenever the buyer's monthly cost is higher than rent, the renter invests the difference; whenever rent is higher, the buyer invests the difference. Both sides therefore deploy the same total budget — the only question is which path leaves you wealthier.
Tax option: When enabled, the mortgage interest and property tax each month are credited back at your marginal rate (a simplification that assumes you itemize).
The chart shows liquidation net worth at each year — i.e. what you'd walk away with if you sold and cashed out at that point — so the crossover marks the year buying pulls ahead.