Putting $100K into a house means going long on real estate and shorting the S&P 500. Every other calculator ignores that. This one doesn't.
The rent vs buy calculator that finally accounts for investment returns — also searched as the buy vs rent calculator.
Buy + hold the property
Monthly costs
Opportunity Cost of Down Payment
That down payment in an S&P index fund would have grown by $137K over the same period.
Rent & invest down payment in S&P 500
Monthly costs
Capital Reallocation View
Buying a home is essentially shorting the S&P 500 to long real estate. Your down payment is capital redirected — not spent.
Equity / portfolio balance after costs
What happens after year 15?
Get the full 30-year projection — year-by-year table, breakeven analysis, printable PDF.
The math behind the biggest financial decision of your life.
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"You get to write off the interest" is the most-repeated argument for buying — and for most households in 2026 it's worth close to nothing. Here's the actual math on the standard deduction hurdle, who still benefits, and the homeowner tax break that's genuinely valuable.
This calculator is for educational purposes only and does not constitute financial advice. Projections are hypothetical and assume constant rates of return. Past performance is not indicative of future results. Selling costs assumed at 6% of home value.
This calculator models the true financial trade-off between buying a home and continuing to rent. Most rent vs buy (or buy vs rent) calculators stop at comparing monthly payments. This one goes further: it treats your down payment as capital that could be invested in the S&P 500 instead of real estate, and shows you which path builds more net worth over your chosen time horizon — accounting for home equity, mortgage amortization, maintenance, property taxes, insurance, selling costs, and the compounding power of investing the monthly savings from renting.
When you put $100,000 into a home, you're reallocating capital — not just spending it. That same $100K invested in an S&P 500 index fund has historically returned around 9–10% annually. The opportunity cost is what that money would have earned in the market over your time horizon. Buying a home is effectively going long on real estate and short on the S&P 500. This calculator shows both sides of that trade, which most rent vs buy calculators ignore entirely.
If renting is cheaper than owning each month — which it often is in expensive markets — the renter has surplus cash. The "invest the difference" toggle assumes that monthly surplus is invested in the S&P 500 at your chosen return rate, rather than spent. This is one of the most important variables in any buy vs rent analysis: without it, the renter scenario is artificially weak and the comparison isn't honest.
These are the hidden costs most mortgage calculators omit. Maintenance typically runs 1–2% of home value per year — on a $500,000 home that's $5,000–$10,000 annually, or $400–$800 per month, none of which builds equity. Add property taxes of 0.3–2.5% depending on your location and the true monthly cost of ownership is often far higher than the mortgage payment alone. These "phantom costs" are a key reason renting beats buying in many short-to-medium time horizons.
Not necessarily. A larger down payment reduces your monthly payment and avoids PMI, but it also pulls more capital out of the stock market. If long-run S&P 500 returns exceed your after-tax mortgage rate, a smaller down payment can produce higher total net worth — even accounting for PMI premiums. Use the down payment slider to explore this tradeoff with your own numbers.
Buying tends to win when you hold the property long enough for equity to compound, home appreciation is strong, your mortgage rate is well below long-run market returns, and transaction costs (typically 6% of sale price) are amortized over many years. The breakeven year in the chart is the point where the homeowner's net worth overtakes the renter/investor's. It varies widely — anywhere from 4 to 20+ years — depending on your local market and assumptions.
The calculator assumes constant annual rates for S&P 500 returns, home appreciation, and mortgage interest. Real markets are volatile and your actual outcome will differ. These projections are most useful for comparing scenarios against each other — for example, "what if I use 10% down instead of 20%?" or "how does a 7% mortgage rate change the breakeven?" — rather than as absolute predictions. They do not constitute financial advice.