Rent vs Buy: The Real Numbers Behind the Headlines

The “rent vs buy” question gets answered in headlines with one-line rules of thumb. The honest answer is: it depends on six numbers, and the right answer changes year by year as those numbers change.

This post walks through the inputs that matter, the common shortcuts that mislead, and how to run the comparison properly for your own situation.

The 6 numbers that decide the answer

1. Monthly rent (and how fast it rises — usually 3-5%/year in most US markets).
2. Purchase price (and how fast the home appreciates — usually 3-5%/year long-term, but very volatile).
3. Mortgage rate (the largest single driver in 2026 — a 1% change in rate is roughly 10% change in monthly payment).
4. Your expected holding period (transaction costs to buy and sell are usually 5-10% of the price; you need to hold long enough to recover them).
5. Opportunity cost of the down payment (the return you would have earned if you kept that money invested in a broad index fund — historically 7-10%/year nominal).
6. Total cost of ownership (property tax, insurance, maintenance, HOA, plus the time cost of repairs).

If any one of these is wrong by a meaningful amount, the answer flips. That is why the headline rules (“renting is throwing money away,” “always buy,” “don’t buy until you have 20% down”) all fail in specific cases.

The basic comparison

Take a 5-year horizon as the default. Assume a $400,000 home, 7% mortgage rate, 20% down ($80,000), 30-year term, and $2,400/month rent.

Cost of renting for 5 years

• Year 1: $2,400 × 12 = $28,800
• Year 2: $2,520 × 12 = $30,240 (5% rent inflation)
• Year 3: $2,646 × 12 = $31,752
• Year 4: $2,778 × 12 = $33,336
• Year 5: $2,917 × 12 = $35,004

Total rent: $159,132

Plus renter’s insurance ($200/year × 5 = $1,000). Plus the opportunity cost: if the $80,000 “down payment” had been invested at 7%, it would be worth $112,308 after 5 years. The opportunity cost is $32,308.

Total cost of renting: $192,440

Cost of buying for 5 years

• Down payment: $80,000 (now in illiquid home equity instead of an index fund)
• Closing costs (buy): ~$12,000 (3%)
• Monthly mortgage (P&I only): $2,128 × 60 = $127,680
• Property tax: $400,000 × 1.2% / year × 5 = $24,000
• Insurance: $1,500/year × 5 = $7,500
• Maintenance: 1%/year × 5 = $20,000
• Closing costs (sell): ~$24,000 (6%, including agent commission)
• Home value at sale: $400,000 × 1.04^5 = $486,663 (4% annual appreciation)
• Loan balance at sale: $307,000 (paid down $13,000 of principal over 5 years)
• Net sale proceeds: $486,663 − $307,000 − $24,000 = $155,663

Total cost of buying (cash out): $80,000 (down) + $12,000 (close buy) + $127,680 (mortgage) + $24,000 (tax) + $7,500 (ins) + $20,000 (maint) + $24,000 (close sell) − $155,663 (proceeds) = $139,517.

For this scenario, buying is $192,440 − $139,517 = $52,923 cheaper over 5 years, primarily because the home appreciated and the mortgage principal got paid down.

When the answer flips

When renting wins

• Short holding period. 3 years or less, transaction costs are unrecovered.
• High mortgage rate, low rent inflation. 8%+ rates with rent locked at 2% annual increases push renting ahead.
• High opportunity cost expectation. If you think the market will return 12%/year and home prices will rise 3%, renting wins by a lot.
• You move for work. Holding period risk is the single biggest cost of buying. A 2-year stint in a new city is essentially never worth buying.
• Stagnant or declining local market. If you are in a market with structural decline (declining population, weak job market), appreciation may be 0-2% for years.

When buying wins

• Long holding period. 7-10+ years, transaction costs amortize and the loan principal gets paid down meaningfully.
• Low mortgage rate, high rent inflation. 5% rate with 6% rent inflation, buying wins on both sides.
• Strong local appreciation. Coastal, supply-constrained markets tend to outpace the national average.
• Stable life situation. You are unlikely to move within 5 years for family, work, or other reasons.

The common mistakes

1. Ignoring opportunity cost. The biggest one. Your $80,000 down payment is gone the day you close. If it would have earned 8% in the market, that is a real cost.
2. Ignoring maintenance, tax, and insurance. These add 30-50% to the mortgage payment in most US markets.
3. Ignoring transaction costs. 8-10% round-trip in the first 5 years means you need the home to appreciate 8-10% before you break even on transaction costs alone.
4. Including the “principal paydown” as a cost. It is not a cost; it is forced savings. You are paying yourself.
5. Using the wrong rent inflation assumption. Most US metros have averaged 3-5%/year over 30 years. Some markets have averaged 6%+. Use the right number for your market.

How to run your own comparison

The Uttir Rent vs Buy Calculator takes all six inputs (rent, price, mortgage rate, holding period, opportunity cost, and rent inflation) and runs the full comparison. The output is a side-by-side cost over your holding period, with the breakeven year and the total cost difference. Runs in your browser with no upload.

For the financing side, the Uttir Mortgage Calculator and Loan Amortization Calculator cover the monthly payment and full schedule. The Rental Yield Calculator is the right tool if you are thinking of buying to rent out instead of living in.

Bottom line

Rent vs buy is a 6-input problem, not a one-line rule. The answer flips on holding period, rate, and rent inflation. The honest answer requires a calculator, not a slogan. Use the Uttir Rent vs Buy Calculator for your specific numbers — runs in your browser, no signup, no upload.