"Rent is throwing money away" is one of the most repeated pieces of financial folk wisdom, and it's also incomplete. Buying has costs that a simple mortgage-payment-vs-rent comparison leaves out entirely. Our Buy vs Rent calculator tries to account for all of them; here's what actually goes into the math.
The opportunity cost of the down payment
A 20% down payment on a house is money that stops being invested in anything else. If that cash would otherwise sit in a diversified portfolio earning a real return, buying has to clear that bar too, not just beat the rent check. This is the single most commonly missed piece of the comparison, and it's often the deciding factor when the numbers are close.
Appreciation is not guaranteed, and it's not free
Home price appreciation gets treated as a certainty in casual conversation, but it's a market return like any other, regionally variable, sometimes flat or negative for years at a stretch, and taxed and transaction-costed on the way out. Whatever appreciation rate you assume, it's worth stress-testing at a lower number too.
Transaction costs cut both ways
Buying and selling a home both carry real costs, closing costs, agent commissions (typically 5-6% combined when you sell), moving costs, and in many places, transfer taxes. These costs mean that buying only makes sense over a long enough holding period to amortize them. If there's a real chance you move in three years, the math tilts hard toward renting even if the monthly payment comparison looks favorable.
What ownership also gives you
None of this is an argument that renting always wins. Buying fixes your housing cost against rent inflation, builds forced equity through principal paydown, and gives you a lever, a mortgage, that lets you control a large asset with a relatively small amount of your own cash. Those are real, and they don't show up in a pure numbers comparison, but they matter to real decisions.
Run your own numbers
The Buy vs Rent calculator lets you plug in your own down payment, mortgage rate, expected appreciation, rent, and how long you expect to stay, and shows you the breakeven point, the holding period at which buying starts to beat renting, given your assumptions. Change the assumptions and watch how much that breakeven point moves; it's usually more sensitive than people expect.