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Real Estate Investor Toolkit

Methodology · Overview

Methodology

Reviewed by · Last reviewed .

Every calculator on Real Estate Investor Toolkit is a real piece of software with tests, a citation to a primary source, and a named human who reviews it. Most real-estate calculators online are run by lead-gen brokers, wholesalers chasing assignment fees, or affiliate aggregators tied to specific lenders. We're not a licensed broker and don't earn commission on whether you actually do the deal — the calculator output is the product. For category-specific methodology — primary sources, formula derivations, edge cases, deal-grade benchmarks, update protocol — see the per-category pages linked at the bottom. For how Bedrocka Tools operates as a publisher more broadly, see our editorial standards.

How tools are built

Calculators are written in TypeScript as pure functions inside a shared package (@bedrocka-tools/calc), with Vitest unit tests that cover edge cases: zero-leverage cap rates, negative-leverage scenarios, BRRRR refi-LTV-shortfall cases, fix-and-flip hold-time slips, IRC §168 depreciation schedules at 27.5 / 39 years, §1031 boot calculations, and every published worked example we can find from primary sources. The package has no UI and no side effects — if a calculator gives the wrong answer, there's one file to fix and a failing test that tells us it was wrong.

Formula sourcing — primary sources only

We only cite primary sources. "Industry-typical" is not a source. Primary sources we use routinely:

  • Fannie Mae Selling Guide — §B6 (multifamily underwriting + DSCR thresholds), §B7-3 (property insurance minimums on conforming mortgages), §B4-1 (appraisal requirements).
  • Aswath Damodaran NYU Stern — sector-level cost of capital, real-estate equity risk premiums, public-REIT comparables for direct-cap derivations.
  • NCREIF Property Index — quarterly cap-rate benchmarks by sector and region for commercial real-estate.
  • Internal Revenue Code — §168 (accelerated cost recovery / depreciation), §1031 (like-kind exchanges), §469 (passive activity loss limitations), §199A (qualified business income deduction).
  • HUD Multifamily Underwriting + FHFA Conforming Loan Limits.
  • Federal Reserve H.15 release for benchmark interest rates + FRED time series for housing-related metrics.
  • BLS CPI shelter component for inflation-adjusted rent growth normalization.

Secondary sources (industry researchers like Marcus & Millichap, CBRE, JLL market reports) are used only where a primary source doesn't directly answer the question — and always labeled as such. Wholesaler blogs, course-creator content, and YouTube guru-channels are NOT cited.

Review process

  1. Draft: calculator logic and explanatory copy are drafted, sometimes AI-assisted, always with the primary source pulled up in parallel and every non-trivial number checked against it.
  2. SME review: each calculator is reviewed by a named human. Byron Malone reviews real-estate-investment content directly given operator-grade experience structuring entity-level ownership, evaluating residential and small-multifamily deals, modeling fix-and-flip economics and BRRRR strategy through more than one cycle. Tax-treatment content involving IRC §1031 / §469 / §199A passes additional CPA review.
  3. Citation verification: every URL cited is spot-checked at publish time and every named rule, threshold, or rate is re-checked against the source document.
  4. Publish: with a Last updated stamp and a dateModified schema.org field on every page.

Update cadence

Every calculator is reviewed on a quarterly cadence. In addition, we update immediately on any of the following triggers:

  • Fannie Mae Selling Guide §B6 or §B7-3 revisions
  • FHFA Conforming Loan Limit annual update
  • IRC §168 / §1031 / §469 / §199A statutory changes (e.g., bonus depreciation phase-down)
  • Federal Reserve rate changes that affect SOFR-indexed and Prime-indexed real-estate debt
  • NCREIF Property Index quarterly publication (cap-rate benchmarks)

Error reporting

If a calculator gives you the wrong answer, we want to hear. Email info@bedrockatools.com with the tool, the inputs you used, and the output you got. We respond to every report within 3 business days; if the tool is wrong, we fix it and publish a correction note on our corrections page.

Per-category methodology

Each calculator category has a dedicated methodology page covering the primary sources, formula derivations, edge cases, and update protocol specific to that category:

  • Income property — cap rate, NOI methodology, cash-on-cash, DSCR, band-of-investment derivation.
  • Fix-and-flip — ARV methodology, hard-money cost structure, holding-cost modeling, the 70%-rule, sale-side closing costs.
  • Financing & underwriting — Fannie Mae conforming financing (1–4 unit residential investment), DSCR loans, commercial financing thresholds. (Stub at launch; full content lands with the next anchor calc.)
  • Tax & depreciation — IRC §168 depreciation schedules, §1031 like-kind exchange mechanics, §469 passive activity loss rules, §199A QBI on rental income.
  • Portfolio strategy — BRRRR strategy math, cap-rate compression cycles, leverage decisioning. (Stub at launch.)

Limitations & non-licensure disclosure

Calculators on this site are estimatesfor educational use. Bedrocka Tools is not a licensed real-estate broker, agent, mortgage originator, or CPA in any state. The tools do not account for every market overlay, every lender's specific underwriting box, every state's recording / transfer / closing cost structure, or the specifics of your individual tax situation. They are not real-estate, investment, financial, legal, or tax advice. Consult a qualified CPA, attorney, and licensed broker for decisions with real dollars attached. The tools are designed to make you a better-informed buyer of professional advice, not a replacement for it.