Renting vs Buying: How to Run the Numbers Yourself

"Rent is throwing money away." "Buying is always an investment." Both lines are repeated constantly and neither survives contact with a spreadsheet. Renting vs buying is an arithmetic question with a different answer in different cities, at different interest rates, and for different lengths of stay. Here is how to work out your own answer.

The mistake almost everyone makes

The usual comparison is rent against the mortgage payment. That is not the comparison. A mortgage payment contains principal, which is savings, not cost. Meanwhile owning carries real costs that renting does not.

What you actually want to compare is rent against the money owning burns that you never get back.

The costs on each side

What renting costs you

Rent, renters insurance, and the return you give up on nothing — your deposit is small and comes back. That is close to the whole list. Renting is expensive but simple.

What owning costs you (beyond principal)

• Mortgage interest — in early years this is most of the payment
• Property tax — roughly 0.5%–2.2% of value a year depending on the state
• Insurance — homeowners, plus flood or wind cover where it applies
• Maintenance — budget about 1% of the property value a year, averaged
• HOA or condo fees, where they exist
• Opportunity cost on the down payment — that cash could have been invested
• Transaction costs — 2%–5% going in, 6%–10% coming out

The quick screen: the 5% rule

For a fast read, add roughly 5% of the property price a year as the unrecoverable cost of owning: about 1% maintenance, about 1% property tax, and about 3% as the combined cost of borrowing and tying up your down payment. Divide by twelve and compare it to the monthly rent on a comparable place.

A $400,000 home: 5% is $20,000 a year, or about $1,670 a month. If a similar home rents for $2,200, buying looks favourable. If it rents for $1,400, renting wins and the gap is money you can invest instead.

The number that usually decides it: how long you will stay

Transaction costs are the hidden hinge. Spending 3% to buy and 8% to sell means roughly 11% of the price has to be earned back through appreciation and principal before you break even against renting. At 3% annual appreciation that is about four years; if prices stay flat it can be seven or more.

So the honest rule of thumb is: under three years, rent. Over seven, buying usually wins. In between, it depends on the numbers above — and on how certain you are about your job and your city.

What the spreadsheet cannot price

Owning buys control: you can renovate, you cannot be told to leave, and after thirty years the payment stops. Renting buys flexibility: you can take a job in another state in a month, and a failed water heater is someone else's problem. Both are worth real money to real people, and neither shows up in the arithmetic.

How to actually do it

1. Price a specific home you would buy and a specific home you would rent — comparable, not aspirational.
2. Total the unrecoverable annual costs of owning, including opportunity cost on the deposit.
3. Compare it to twelve months of rent plus renters insurance.
4. Add transaction costs and divide by your realistic years of staying.
5. Then decide what the flexibility or the control is worth to you, and let that break a close call.

The CFPB's home-buying tools are a good neutral place to check mortgage assumptions. And if the down payment is still forming, start with the emergency fund — buying with no cash buffer is how a house becomes a crisis.