Real Estate Investor Toolkit · Bedrocka Tools
Real-estate investor math without the
guru-podcast agenda.
Most real-estate calculators online are run by lead-gen brokers, wholesalers chasing assignment fees, or affiliate aggregators tied to specific lenders. This site is the opposite: every formula is open-source, every assumption cites the primary source (Fannie Mae multifamily underwriting, Damodaran NYU Stern datasets, NCREIF benchmarks, IRC §168 / §1031 / §469), and every tool is reviewed quarterly by a named operator.
Calculators
Pick the deal-math you actually need.
Income Property
Cap Rate Calculator
Cap rate (capitalization rate) = NOI (Net Operating Income) / property value — the foundational income-property metric. With direct-cap valuation reverse and band-of-investment derivation (a 'fair' cap rate from underlying debt + equity costs).
Open calculator →Rental Property Cash Flow Calculator
Full pro-forma: gross rent, vacancy, operating expenses, debt service → NOI (Net Operating Income), cash flow, cash-on-cash return, DSCR (Debt Service Coverage Ratio). With CapEx (capital expenditures) reserve modeling and 5-year IRR (Internal Rate of Return) projection.
Open calculator →
Portfolio Strategy
BRRRR Deal Modeler
BRRRR (Buy, Rehab, Rent, Refinance, Repeat) strategy math with honest numbers. 5-scenario sensitivity: target case + 3 single-failure modes (rehab over, appraisal light, refi LTV constrained) + combined-failure case. Surfaces capital recovered vs capital stuck, post-refi cash flow, DSCR (Debt Service Coverage Ratio) per scenario.
Open calculator →Rent vs Buy Calculator
Operator-grade rent vs buy decision math with the differentiator most online calculators skip — opportunity cost on the down payment + closing costs. Compares total cost over hold period including renter's invested-capital growth at user-specified return. Cited to IRC §163(h), §164 SALT cap, Damodaran NYU Stern.
Open calculator →
Learn
Concepts behind the deal math.
Income Property
What cap rate actually means — and where the metric breaks
Cap rate = NOI / value. The metric works well for comparing comparable income properties at scale and breaks down in three specific scenarios most investors have to navigate. Here's the math, the mechanics of the band-of-investment derivation, and where the metric stops being useful.
Portfolio Strategy
BRRRR strategy: the math with honest numbers
The BRRRR pitch — pull all your capital back out, do it again with the same money — works on YouTube and breaks on real timelines. Here's the actual math when rehab runs over, the appraisal comes in light, the refi LTV is 70 not 75, and the 'all your money back' becomes 'most of your money back.'
What makes this different
Three things every Bedrocka Tools site does that the real-estate-guru sites don't.
Open-source math
Every calculator's formula is published as TypeScript with Vitest tests in a public repo. Click "View source" in any math accordion to see the actual implementation. The big real-estate calculator sites hide their math behind paywalls and email captures. We publish ours.
Browse the math →Primary-source citations only
Every cap-rate range, every depreciation rule, every lender threshold links to the original document — Fannie Mae Multifamily Selling Guide §B6, Damodaran NYU Stern datasets, NCREIF NPI quarterly reports, IRC §168 / §1031 / §469 / §199A. No "industry-typical" hedging. The citation is the proof.
Read the methodology →Named operator, no commission
Reviewed and signed by Byron Malone— operator-grade experience structuring entity-level ownership, evaluating residential and small-multifamily deals through more than one cycle. Not a wholesaler. Not a guru course. Nothing here earns a commission tied to whether you do the deal.
Read Byron's bio →