Rent vs. Buy Calculator: True Cost Comparison for Families

The popular framing — "renting is throwing money away" — ignores the opportunity cost of a $150K down payment and the $30K in closing costs and maintenance you'll pay in year one. This calculator runs both scenarios side-by-side over your actual time horizon and tells you which one leaves your family with more money.

Why "you're just paying rent to your landlord" is only half true

Every homeownership advocate trots out the equity argument. And it's real — a mortgage payment does build equity, while rent does not. But there's a mirror image: the down payment and closing costs you hand over on day one are not sitting in your home, they're sitting in an illiquid asset you can't touch without selling or borrowing against it.

A family that buys a $600,000 home with 20% down ties up $120,000 plus $15,000 in closing costs — $135,000 of capital that a renter keeps invested. At 7% per year, that $135,000 grows to roughly $216,000 over 7 years. That's $81,000 in investment gains the buyer gave up. This is not free. The calculator accounts for it.

The honest comparison isn't "mortgage payment vs. rent payment." It's the net cost of each path — total out-of-pocket minus wealth recovered — over your actual planning horizon.

The hidden costs of homeownership most calculators ignore

Standard mortgage calculators show you principal, interest, taxes, and insurance. They skip three categories that materially affect the true cost:

• Maintenance. The long-run average for home maintenance is 1–2% of home value per year³ — roof, HVAC, appliances, plumbing, landscaping. On a $600,000 home, that's $6,000–$12,000/year. This calculator uses 1%, the conservative end. In practice, costs cluster: new HVAC might be zero for 10 years, then $12,000 in one year.
• Closing costs. Buying costs you 2–3% of the purchase price in lender fees, title insurance, inspection, and prepaid items. Selling costs you another 5–6% in realtor commissions and transfer taxes. The calculator uses 2.5% to buy and 6% to sell.
• PMI if under 20% down. Private mortgage insurance at ~0.85%/year is required by conventional lenders when LTV exceeds 80%⁴. On a $480,000 loan, that's $4,080/year. PMI cancels when your loan balance hits 78% of the original purchase price. Under OBBBA (2025), PMI is now treated as deductible mortgage interest for 2026².

Break-even analysis: how long do you need to stay?

The break-even year is when cumulative net buying costs drop below cumulative net renting costs. For most U.S. markets, this falls between 4 and 8 years — depending heavily on:

• How fast home prices are appreciating. A 5%/year appreciation market breaks even faster. A 2%/year market takes longer.
• How fast rent is rising. High rent inflation favors buying sooner. Stable rent favors waiting.
• Your investment return on the alternative. If you'd invest the down payment in bonds at 4%, buying wins sooner. If you'd invest in equities at 9%, renting stays competitive longer.
• Transaction costs. The ~8.5% combined buy/sell transaction cost (2.5% buying + 6% selling) is the biggest drag on short-horizon buyers. A family that moves after 3 years rarely breaks even.

The conventional wisdom "buy if you're staying 5+ years" is a reasonable heuristic. But your actual number depends on your market, down payment size, and how disciplined you'd actually be about investing the down payment alternative.

Tax considerations for homeowners in 2026

Three tax rules shape the buy vs. rent math for families in 2026:

Mortgage interest deduction (MID). Interest on up to $750,000 of acquisition indebtedness is deductible if you itemize¹ (TCJA §11043, now permanent under OBBBA). With the 2026 standard deduction at $32,200 for married filing jointly¹, itemizing only helps if your mortgage interest + state taxes (capped at $40,400 SALT) + charitable giving exceeds $32,200. On a $480,000 loan at 6.75%, year-one interest is ~$32,200 — right at the threshold. Most families with mortgage balances above ~$450,000 in moderate-to-high property tax states will benefit from itemizing.

PMI deductibility (new in 2026). OBBBA (2025) treats mortgage insurance premiums as deductible mortgage interest for 2026². If you're buying with less than 20% down, the PMI you pay is now a tax-deductible expense. This meaningfully reduces the effective cost of a smaller down payment.

Home sale capital gains exclusion (§121). When you sell your primary residence after owning and living there at least 2 of the last 5 years, the first $500,000 of gain (MFJ) or $250,000 (single) is excluded from capital gains tax⁴ — unchanged since 1997, not modified by OBBBA. This exclusion is enormous: it means most families pay zero capital gains tax when they sell their home, regardless of appreciation.

How the buy vs. rent decision interacts with family financial priorities

Housing doesn't exist in isolation. It competes with retirement, college savings, insurance coverage, and emergency reserves. A few family-specific framing points:

Don't let the down payment crowd out 401(k) matches. If saving the down payment means you're leaving employer 401(k) match on the table, that's an immediate 50–100% guaranteed return you're giving up. Capture the full match first, always — even if it delays your purchase by 12–18 months. See our 401(k) vs. 529 prioritization framework.

The mortgage shouldn't be too large to absorb a one-income shock. Dual-income families often buy homes calibrated to combined income. If one earner takes parental leave, switches to part-time, or loses a job, can you make payments on one salary? A useful stress test: run the affordability calculator with only the higher earner's income. If the result is still your target price, you're in good shape.

Owning a home increases your emergency fund target. Renters can cover job loss with 3 months of expenses. Homeowners need 4–6 months — because a furnace failure and an income disruption can happen simultaneously, and you can't walk away from a mortgage the way a renter can skip a lease renewal. See our family emergency fund calculator.

Estate planning changes when you own a home. A house is often the largest asset in a family's estate. Make sure your will, revocable trust (if applicable), and beneficiary designations are updated after closing. See our estate planning guide.

1. IRS Publication 936 (2025), "Home Mortgage Interest Deduction" — $750,000 acquisition indebtedness limit (TCJA §11043, made permanent by OBBBA 2025); 2026 standard deduction $32,200 MFJ from IRS Rev. Proc. 2025-32; SALT cap $40,400 MFJ (OBBBA 2025). irs.gov/publications/p936. Values verified 2026.
2. OBBBA (One Big Beautiful Bill Act, July 2025) — treats mortgage insurance premiums as deductible acquisition indebtedness interest beginning tax year 2026. IRS OBBBA provisions page: irs.gov/newsroom/one-big-beautiful-bill-provisions.
3. National Association of Home Builders, "What It Costs to Own a Home" — ongoing maintenance and repair costs average 1–2% of home value annually. nahb.org. The 1% floor is widely cited as a minimum reserve; older homes and deferred-maintenance properties run higher.
4. IRC §121 (Taxpayer Relief Act of 1997) — $500,000 MFJ / $250,000 single exclusion on gain from sale of primary residence; 2-of-5-year ownership + use requirement. Not modified by OBBBA. law.cornell.edu/uscode/text/26/121. PMI automatic cancellation under Homeowners Protection Act of 1998 (12 U.S.C. § 4901) at 78% LTV.

Sources verified May 2026. Tax values reflect 2026 tax year.