Rent vs Buy Calculator

Yes, the RoughTools Rent vs Buy Calculator is completely free with no subscription, account, or payment required. You can run as many comparisons as you need — adjusting home price, mortgage rate, rent, appreciation rate, and time horizon — all at no cost. RoughTools is funded through non-intrusive advertising, which keeps every calculator permanently free for homebuyers, renters, and financial planners worldwide.

No account, email address, or registration is required. Open the page, enter your numbers, and click Calculate — results appear instantly. There is no paywall on any input or result, and no upgrade required to see the full comparison breakdown. All calculations run in your browser with no data transmitted to any server or stored in any database.

No. All calculations run entirely in your browser using JavaScript. The home price, income, mortgage rate, rent figures, and all other inputs you enter are never transmitted to RoughTools servers, never logged, and never shared with third parties. Once you close the tab, the data is gone. Your financial information remains completely private throughout the entire process.

Yes, the calculator is fully responsive and works on all modern smartphones and tablets running iOS 14+ or Android 8+. All input fields, sliders, and result panels are optimised for touch screens. The comparison chart and cost breakdown display clearly on smaller screens. This is particularly useful when you are at an open house and want to quickly compare your rental costs against buying the property you are viewing.

The Rent vs Buy Calculator works in all modern browsers: Google Chrome, Mozilla Firefox, Microsoft Edge, Safari, Opera, and Brave — on both desktop and mobile. No plugins or extensions are required. The calculator uses standard JavaScript arithmetic that runs natively in every modern browser. For the best experience with number formatting and currency display, any current version of Chrome, Firefox, or Safari is recommended.

The accuracy depends entirely on the quality of your inputs. The calculator uses standard amortisation formulas for mortgage payments and compound interest for investment returns — these are mathematically precise. The key uncertainties are future assumptions: home appreciation, rent increases, and investment returns. The tool provides a best-estimate scenario based on your inputs. For a financially consequential decision like buying a home, treat the results as a planning guide and consult a licensed financial adviser for a personalised analysis.

The calculator runs in your browser using JavaScript, so once the page has fully loaded, you can continue using it without an active internet connection. You can adjust inputs and recalculate results offline. However, the initial page load requires an internet connection to download the page assets. For fully offline use, you would need to save the page locally — but for most users, the page loads quickly and works seamlessly on any connection speed.

To run a comparison: (1) Enter the home price you are considering and your expected down payment percentage. (2) Set the mortgage interest rate and loan term (typically 30 years). (3) Enter estimated property tax rate and annual maintenance cost as a percentage of home value. (4) Enter your current or expected monthly rent and the annual rent increase percentage. (5) Set the expected annual return on investments — the opportunity cost of the down payment if you rented instead. (6) Click Calculate to see the 10-year net cost comparison for buying versus renting.

RoughTools Rent vs Buy Calculator includes opportunity cost — the investment return you could earn on the down payment if you rented instead of buying. Many basic calculators ignore this critical factor, making buying appear cheaper than it truly is. This calculator also accounts for home appreciation reducing your net buy cost over time, and rent increases increasing your total rental cost. The result is a more complete and honest comparison of both options over your chosen time horizon.

To report a bug or request a feature — such as comparison graphs, tax deduction modelling, PMI inclusion, or state-specific tax rates — use the feedback link in the site footer or visit the RoughTools contact page. When reporting a bug, include the inputs you used, the browser and operating system, and what result you expected versus what was displayed. Feature requests for additional scenarios such as ARM mortgages, HOA fees, or rental income from owner-occupied properties are reviewed and prioritised regularly.

Opportunity cost is the return you forgo by putting money into a down payment instead of investing it elsewhere. If you make a $80,000 down payment, that $80,000 cannot be invested in stocks, bonds, or other assets. Over 10–30 years, the compounded growth of that capital is significant. The Rent vs Buy Calculator models this by assuming the down payment would be invested at your specified annual return rate if you rented instead. This often makes renting financially competitive with buying, especially in high-price markets.

The net cost figure represents your total financial outlay minus the value you received in return. For buying, it is total mortgage payments + property taxes + maintenance, minus the home equity you built (current home value minus remaining loan balance). For renting, it is total rent paid minus the investment growth of the down payment if it had been invested. A lower net cost means that option left you in a better financial position over the comparison period. The winner depends heavily on home appreciation, investment returns, and your time horizon.