Practical digital tools for real estate decisions
Roof & Ratio by Marchelle creates downloadable calculators, planners, trackers, workbooks, and guides for homebuyers, homeowners, investors, landlords, contractors, and real estate professionals. The tools help you organize information, compare assumptions, and understand the numbers behind a property decision.
Roof & Ratio was founded by Marchelle Cook, whose background includes real estate sales, investing, renovations, and property management in Texas and Florida.
Find the right starting point
- Understand a mortgage: use the Mortgage Amortization & Extra Payment Calculator to compare schedules and estimated interest savings.
- Evaluate a rental or flip: use the Rental Property Cash Flow Calculator & Deal Analyzer to organize income, expenses, financing, and return estimates.
- Prepare for a lender conversation: use the Mortgage Pre-Approval Readiness Checklist to organize documents and estimate DTI.
Browse all digital products or read the Real Estate Tips & Guides before choosing a tool.
Formats and delivery
Products are digital downloads, and the product page identifies the included files and features. Interactive HTML tools open in a modern web browser; PDFs require a compatible reader. The mortgage and deal-analysis calculators are HTML tools, not Excel or Google Sheets workbooks. These downloadable products are one-time purchases, and no physical item is shipped.
Read How Digital Downloads Work and the frequently asked questions for device, saving, and printing details.
Editorial standards: how we explain the numbers
Our worked examples state the assumptions needed to follow the calculation. Fictional examples illustrate a method; they are not customer outcomes, lender offers, market averages, or promises of a return.
- Mortgage example: the published comparison uses a new $300,000 loan, fixed 6.5% annual interest, monthly payments over 30 years, and extra principal beginning with the first payment. It excludes taxes, insurance, fees, and penalties.
- Rental example: the published cash-flow budget separates operating expenses, debt service, and capital reserves. It labels whether a return includes a reserve allowance.
- DTI example: the published calculation divides the stated monthly debt obligations by gross monthly income. Loan-program requirements and lender decisions remain separate.
Use your property records and lender figures, check omitted costs, and compare scenarios before relying on an estimate. If you spot an unclear instruction or calculation, contact marchelle@roofandratio.com with the product name and a non-sensitive example.
For educators, writers, and collaborators
The public guides include calculation explanations and examples you can link to when discussing mortgage payments, rental analysis, or homebuyer preparation. For product questions or an interview request, contact Roof & Ratio. Please identify the specific guide or tool so we can respond to the right topic.
Free ratio calculator for everyday math
Use MyRatioTable, our free online ratio calculator, to simplify ratios, find a missing value, scale a recipe quantity or split a shared cost. Includes worked examples and an equivalent ratio table. It opens in your browser with no purchase, download or signup required.