Key takeaways
- The comparison counts what you'd walk away with, not just what you pay: home equity after selling costs for buyers, invested savings for renters.
- Rent, rent growth, appreciation, investment return, maintenance and selling costs are your assumptions; change them and see how the answer moves.
- Property tax and insurance use Oklahoma data, including the 3% yearly cap on a homestead's value increases.
How the comparison works
Both paths get the same monthly budget. Each month, whichever path is cheaper invests the difference, and the renter invests the cash the buyer would have put into the down payment and closing costs. At the end of each year the calculator asks: if you stopped here (the buyer sells, paying selling costs and the rest of the loan; the renter just stops), what did each path cost?
Net cost = cash put in − what you walk away with. The path with the lower net cost came out ahead. The break-even year is the first year buying does.
What comes from data, and what's yours
| Input | Starting value |
|---|---|
| Interest rate | Freddie Mac PMMS weekly average (data) |
| Property tax | Your county's or Oklahoma County district's levy and assessment percentage, homestead exemption (data) |
| Insurance | Oklahoma statewide average, $5,298 a year (data) |
| Value growth cap for property tax | 3% a year for a homestead, 5% otherwise (Okla. Const. art. 10, § 8B) |
| PMI | Midpoint of Freddie Mac's $30–$70 per $100,000 range, ending at 78% of the original value (estimate) |
| Rent | Blank: you enter it |
| Rent increase, home value growth, investment return, maintenance, selling cost | 3%, 3%, 5%, 1% and 6%: neutral starting points labeled as assumptions, not forecasts |
We don't prefill rent. Public rent benchmarks such as HUD's Fair Market Rents and the Census Bureau's American Community Survey need API accounts we haven't set up, and a county average wouldn't describe the specific place you'd rent anyway.
Reading the result
- How long you stay matters most. Buying has large one-time costs (closing costs now, selling costs later), and the longer you stay, the more years they're spread over.
- Try a few assumptions. Change home value growth and investment return by a point or two and watch the break-even year move.
- Oklahoma specifics are built in: district-level property tax in Oklahoma County, the homestead exemption and 3% value cap, and the state's high average insurance, which the model grows with the home's value.
What the model leaves out
Income taxes are ignored: the mortgage interest deduction, tax on investment gains and any tax on the home sale. Renter's insurance, moving costs and the value of stability aren't counted. The first year's property tax assumes the assessor values the home at the price you pay.
The model
Budget each month = max(owner cost, rent) Investments grow monthly at (1 + return)^(1/12) − 1 and receive budget − own cost Buyer wealth = value × (1 − selling %) − loan balance + buyer investments Net cost = cash in − wealth
- owner cost
- P&I + property tax + insurance + maintenance + PMI + HOA
- value
- price grown monthly at your appreciation rate
- tax
- on fair cash value, which grows at most the § 8B cap each year
For the full monthly payment on a specific home, use the mortgage calculator.
Data this page uses
| Value | Data as of | Source |
|---|---|---|
| Freddie Mac 30-year fixed average7.40% | Week of Oct 8, 2026 | Freddie Mac: Primary Mortgage Market Survey® history (CSV) |
| Freddie Mac 15-year fixed average6.73% | Week of Oct 8, 2026 | Freddie Mac: Primary Mortgage Market Survey® history (CSV) |
| Oklahoma County levies by district code119 codes, 76 combinations (e.g. code 200: 122.90 mills) | Tax year 2025, certified Nov 17, 2025 | Oklahoma County Assessor: Oklahoma County Tax Rates/Millages for 2025 |
| County effective millage, 77 countiese.g. Oklahoma 119.506, Tulsa 127.479 mills | Tax year 2024 | Oklahoma Tax Commission (OTC), Ad Valorem Division: 2024 Ad Valorem Statistics |
| Real property assessment percentage, 77 countiese.g. Oklahoma 11.00%, Comanche 11.25% | 2024 | Oklahoma Tax Commission (OTC), Ad Valorem Division: 2024 Ad Valorem Statistics |
| Homestead exemption$1,000 of assessed value | Current | Oklahoma County Assessor: Homestead Exemption |
| Annual cap on fair cash value increases3% homestead · 5% other | Current (Okla. Const. art. 10, § 8B) | Oklahoma Tax Commission (OTC), Ad Valorem Division: 2024 Ad Valorem Statistics |
| Oklahoma average homeowners insurance$5,298/yr (U.S. $2,395) | Published Jun 8, 2026 | LendingTree: State of Home Insurance: 2026 |
| Conventional PMI range$30–$70/mo per $100,000 (default $50, midpoint) | Checked Oct 8, 2026 | Freddie Mac (My Home): Breaking down PMI |
Questions
Why do I have to enter the rent?
Because the right number is the rent for a place like the one you'd buy, which no county average captures. We also haven't loaded HUD or Census rent data yet, since both need API accounts.
Are the appreciation and investment return predictions?
No. They're neutral starting values, labeled as assumptions. Nobody knows future returns; try several values to see how sensitive the answer is.
What does 'net cost' mean?
All the cash you put in over the period minus what you'd have at the end: for a buyer, the home's sale price after selling costs minus the remaining loan, plus any savings invested along the way; for a renter, the invested savings.
Does the model include Oklahoma's property tax cap?
Yes. Taxable fair cash value grows with the home's value but no faster than 3% a year with a homestead exemption (5% without), per Oklahoma Constitution art. 10, § 8B as summarized by the Tax Commission.
Sources
- Freddie Mac, Primary Mortgage Market Survey® history (CSV). www.freddiemac.com/pmms/docs/PMMS_history.csv Effective Oct 8, 2026; retrieved October 8, 2026.
- Oklahoma County Assessor, Oklahoma County Tax Rates/Millages for 2025. docs.oklahomacounty.org/assessorWP5/taxrates.htm Effective Nov 17, 2025; retrieved October 8, 2026.
- Oklahoma Tax Commission (OTC), Ad Valorem Division, 2024 Ad Valorem Statistics. oklahoma.gov/content/dam/ok/en/tax/documents/resources/publications/ad-valorem/2024StatBook.pdf Effective 2024; retrieved October 8, 2026.
- LendingTree, State of Home Insurance: 2026. www.lendingtree.com/insurance/state-of-home-insurance/ Effective Jun 8, 2026; retrieved October 8, 2026.
- Freddie Mac (My Home), Breaking down PMI. myhome.freddiemac.com/buying/breaking-down-pmi Effective Oct 8, 2026; retrieved October 8, 2026.
How this page is checked
Every number on this page links to a public source. See the methodology for formulas and data refresh dates. Last reviewed October 8, 2026.