Rent vs. Buy: The Real Math Beyond the 1% Rule

The real question

The real question isn't "rent vs. buy." It's: are your unrecoverable costs of owning lower than the rent you'd otherwise pay? This guide shows you how to compute that honestly.

The 5% rule: unrecoverable costs of ownership

Not every dollar of homeownership builds wealth. Three costs are gone forever — you'll never see them again whether the house appreciates or not:

1. Property taxes — roughly 1% of home value per year (varies by state; ~0.7% in California under Prop 13 for long-held homes, over 2% in New Jersey and Illinois)
2. Maintenance and repairs — roughly 1% of home value per year, averaged over time (a new roof doesn't care about your budget)
3. Cost of capital — roughly 3% of home value per year: the mortgage interest you're paying plus the return your down payment isn't earning invested elsewhere

Total: ~5% of the home's value per year is unrecoverable. This is the essence of the "5% rule" popularized by financial researchers.

Worked example: the $600,000 house

• Unrecoverable ownership costs: $600,000 × 5% = $30,000/year = $2,500/month
• Comparable rent: let's say $2,800/month

On pure math, renting wins by $300/month — $3,600/year — even before counting the flexibility. If comparable rent were $2,200/month instead, buying would win by $300/month.

Notice what this framework ignores on purpose: principal paydown (that's savings, not cost) and appreciation (that's speculation, not guaranteed). The 5% rule compares costs, which is the only fair fight.

The costs the 5% rule doesn't include

The 5% rule is a screening tool, not the full picture. Three more factors move the needle:

Transaction costs: the round-trip toll

• Buying: 2–5% of price (closing costs, fees, points)
• Selling: 6–10% of price (agent commissions, closing costs, prep)

On a $600,000 home, a full buy-sell round trip can cost $50,000–$90,000. This is why time horizon dominates the decision: those costs amortize over your years of ownership. Sell after 2 years and you've paid ~$3,000/month in transaction costs alone. Hold for 10+ years and they fade to background noise.

Rule of thumb: if you might move within 5 years, renting usually wins. Beyond 7–10 years, buying usually wins (assuming comparable rent-vs-price math).

Opportunity cost of the down payment

A $120,000 down payment (20% of $600,000) invested at a 7% expected return becomes roughly $236,000 in 10 years. That $116,000 of foregone growth is a real cost of buying — it's already inside the 5%'s "cost of capital," but it's worth seeing explicitly because it grows with time. The longer your horizon, the larger this number gets, which is one reason the math can favor renting even over long periods in very expensive markets.

Leverage and appreciation: the upside case for buying

Here's what renting can't replicate: leverage. With 20% down on a $600,000 home, a 3% annual appreciation ($18,000) is a 15% return on your $120,000 down payment — before principal paydown. In rising markets, leverage is why homeowners build wealth faster than the 5% rule suggests.

But leverage is symmetric. In a flat or falling market, that same leverage amplifies losses, and you're still paying the 5% unrecoverable costs. Never buy because of expected appreciation — buy when the cost math works, and treat appreciation as a bonus.

When renting wins (it's more often than people think)

• Expensive coastal markets. When price-to-rent ratios exceed ~20x annual rent (a $600,000 home renting for $2,500/month = 20x), the 5% rule almost always favors renting.
• Short or uncertain time horizons. Under 5 years, transaction costs usually kill the buying case.
• High property-tax states. At 2%+ property tax, the unrecoverable cost jumps to ~6% of value per year.
• Careers requiring mobility. The option value of being able to move for a 20% raise dwarfs most rent-vs-buy spreads.

When buying wins

• You'd stay 7–10+ years. Transaction costs amortize; principal paydown compounds; the mortgage payment stays fixed while rents rise.
• Rents are high relative to prices. In many Midwest and Southern markets, the monthly math favors buying decisively.
• You value control and stability. Not everything is math. Fixed housing costs, no landlord, your own walls — these have real value, just don't pretend they're free.
• Inflation protection. A fixed-rate mortgage is a 30-year short position on the dollar. As rents and wages inflate, your biggest housing cost doesn't.

The coastal problem: when the math never works

In markets like San Francisco or New York, price-to-rent ratios can exceed 30x — a $1.2M condo renting for $3,200/month. At 5% unrecoverable costs, owning costs $5,000/month against $3,200 rent. Buying never wins on math there unless rents explode or you stay 20+ years.

That's not a broken model — it's information. It tells you the market is pricing in appreciation expectations you shouldn't count on. Options: rent and invest the difference aggressively (the disciplined version of this builds enormous wealth), buy much less house than you can afford, or relocate. What you shouldn't do is buy at 30x rent while telling yourself "renting is throwing money away."

House hacking: changing the equation

One legitimate way to beat the math: house hacking — buying a multi-unit property, living in one unit, and renting the others. If rental income covers most of the mortgage, your personal unrecoverable cost collapses. Example: $800,000 duplex, $4,000/month total housing cost, $2,600/month rental income from the other unit → your effective cost is $1,400/month, far below market rent. It comes with landlord headaches, but it's the main strategy that structurally flips expensive markets.

Common mistakes

Mistake 1: Comparing mortgage payment to rent

"My mortgage would be $2,900 and rent is $2,800, so it's basically the same!" No — roughly half of that early mortgage payment is interest, plus tax, insurance, and maintenance on top. Compare unrecoverable costs to rent, not the mortgage check to rent.

Mistake 2: Ignoring transaction costs entirely

Online calculators that skip the 6–10% selling cost are lying by omission. On a $600,000 home, that's $36,000–$60,000 you only discover at closing.

Mistake 3: Treating the down payment as "spent"

It's not spent — it's invested in the house, earning (maybe) appreciation. But it has an opportunity cost, and calculators that ignore it flatter buying.

Mistake 4: Assuming appreciation

"Real estate always goes up" felt true from 2012–2022 and false in 2007–2011. Run the math at 0% appreciation. If buying still wins, it's a genuinely good deal. If it needs 5% annual appreciation to work, you're speculating.

Mistake 5: Forgetting rent increases

The 5% rule is a snapshot. Rents historically rise ~3% a year; your fixed mortgage payment doesn't. Over a 10-year horizon, rising rents steadily improve the buying case.

The bottom line

Buying isn't universally smart and renting isn't universally dumb. There's a number — your unrecoverable cost of ownership versus market rent — and it decides. Compute it honestly, include the transaction costs, be skeptical of appreciation assumptions, and let the math override the cultural script.

Run your numbers

Our free rent vs. buy calculator models unrecoverable costs, transaction fees, rent inflation, opportunity cost, and your time horizon — and tells you the break-even year.

Open the Rent vs Buy Calculator →

Related calculators

• Rent vs Buy — unrecoverable costs vs. rent, with your time horizon.
• Mortgage Payoff — how extra payments shorten your loan.
• Home Equity — lump sum vs. HELOC vs. cash-out refinance.