What formulas does RentalInvestCalc use for rental property analysis?

RentalInvestCalc uses industry-standard formulas: Cap Rate = Net Operating Income (NOI) ÷ Purchase Price; Cash-on-Cash Return = Annual Cash Flow ÷ Total Cash Invested; NOI = Effective Gross Rent − Operating Expenses (property tax, insurance, maintenance, management, vacancy). All formulas follow IRS Publication 527 and standard real-estate finance definitions.

How is rental property depreciation calculated in the tax calculator?

The IRS allows residential rental property to be depreciated over 27.5 years using the straight-line method (IRS Publication 527). Commercial rental property is depreciated over 39 years (IRC § 168). The annual depreciation deduction equals the depreciable basis (purchase price minus land value) divided by the recovery period. Only the building value is depreciable — land is not.

What is the BRRRR strategy and how does the calculator model it?

BRRRR stands for Buy, Renovate, Rent, Refinance, Repeat. The calculator models each phase: (1) Buy — acquisition cost; (2) Renovate — rehab budget; (3) Rent — projected monthly rent; (4) Refinance — max cash-out at target LTV (typically 75%); (5) Repeat — cash left in deal after refinance. An 'infinite return' occurs when the refinance covers 100% of acquisition + rehab costs.

Where does RentalInvestCalc get its market data and benchmarks?

All market benchmarks are sourced from publicly available official reports: HUD Fair Market Rent data for regional rent benchmarks; FHFA for investment-property mortgage policy; the Census Bureau American Community Survey for macro housing-cost statistics; and NAA research for operating-cost averages. IRS publications (527, 946) govern all tax and depreciation calculations.

Is RentalInvestCalc a substitute for a CPA or real estate professional?

No. RentalInvestCalc is an educational estimation tool only. It does not provide licensed CPA tax advice, legal advice, or professional real estate guidance. All calculations are estimates based on user inputs. Consult a licensed CPA for tax planning, and a licensed real estate professional before making any investment decision.

About RentalInvestCalc — Methodology, Formulas & Data Sources

📐 Core Calculation Formulas

All calculators use industry-standard formulas aligned with IRS publications and NMHC research standards.

Cap Rate

Cap Rate = NOI ÷ Purchase Price

Measures unleveraged return. A rate above 6% is generally considered good for residential rentals (NMHC 2024).

Cash-on-Cash Return

Cash-on-Cash = Annual Cash Flow ÷ Total Cash Invested

Measures leveraged return on actual cash deployed (down payment + closing costs + rehab).

Net Operating Income (NOI)

NOI = Effective Gross Rent − Operating Expenses

Operating expenses include property tax, insurance, maintenance, property management, and vacancy loss. Does NOT include mortgage payments or depreciation.

1% Rule (Quick Screen)

Monthly Rent ≥ 1% of Purchase Price

A quick screening heuristic. Properties meeting the 1% rule are more likely to cash flow in most markets.

📋 IRS Depreciation Rules

The tax depreciation calculator is based on official IRS publications. Always verify with your CPA.

Property Type	Recovery Period	Authority	Method
Residential Rental Property	27.5 years	IRS Publication 527	Straight-line (Mid-month convention)
Commercial Rental Property	39 years	IRC § 168	Straight-line (Mid-month convention)
Land	Not depreciable	IRS Pub 527	N/A

Note: Only the building value (purchase price minus land value) is depreciable. The IRS requires using the mid-month convention for real property. Bonus depreciation and Section 179 may apply to certain improvements — consult IRS Pub 946 for details.

🔄 BRRRR Strategy Calculation Method

The BRRRR calculator models the full investment cycle across five phases:

Buy

Acquisition cost = Purchase price + closing costs. Enter your all-in offer price.

Renovate

Rehab costs are added to total capital invested. After renovation, the After Repair Value (ARV) is estimated.

Rent

Projected market rent determines ongoing cash flow after refinance. Vacancy and expenses are modeled.

Refinance

Cash-out refinance at target LTV (typically 75%). Loan amount = ARV × LTV%. The refinance covers acquisition + rehab if LTV is high enough.

Repeat

Cash left in deal after refinance. If $0 remains, this is an "infinite return" — the holy grail of BRRRR.

📊 Data Sources & Benchmarks

IRS Publication 527 (Residential Rental Property)

Governs depreciation recovery periods, mid-month convention, and what improvements are depreciable vs. expensable. Used in Tab 4 (IRS Depreciation Calculator).

HUD Fair Market Rent (FMR) Data

Regional fair-market rent benchmarks that anchor return-on-investment baselines and state-by-state rent comparisons.

FHFA Investment-Property Mortgage Policy

Authoritative loan-limit and underwriting standards that shape our mortgage and loan-comparison calculators.

U.S. Census Bureau — ACS

Macro housing-cost statistics — vacancy rates, price-to-rent ratios, and regional market context behind our state guides.

NAA Operating-Cost Research

Industry-average operating costs and vacancy-loss figures that improve our expense and reserve assumptions.

🏅 Our Commitment to Accuracy & Transparency

RentalInvestCalc is built on three principles:

✅ Verified Formulas

All calculation formulas are based on industry-standard definitions from IRS publications (527, 946), NMHC research, and CFPB mortgage guidelines. No "black box" calculations.

✅ Public Data Sources

Market benchmarks reference only publicly available, citable U.S. government and nonprofit sources: IRS.gov, HUD User, FHFA, the Census Bureau (ACS), and the National Apartment Association. No proprietary or undisclosed data models.

✅ No False Credentials

RentalInvestCalc does not claim CPA certification, legal licensure, or real estate broker credentials. We are a free educational tool. All tax estimates should be verified with a licensed CPA.

⚖️ Compliance & Disclaimer

Not Financial or Tax Advice: RentalInvestCalc provides estimates for educational purposes only. All calculations are based on user-provided inputs and standard industry formulas, but do not account for your personal financial situation, local tax laws, or changing market conditions.

No Professional Relationship: Use of this website does not create an accountant-client, attorney-client, or broker-client relationship. No fiduciary duty is established.

Consult Professionals: Before making any real estate investment decision, consult with: (1) a licensed CPA for tax implications; (2) a licensed real estate professional for local market conditions; (3) a licensed mortgage professional for financing options.

Data Accuracy: While we strive for accuracy, RentalInvestCalc makes no warranties about the completeness, reliability, or accuracy of the calculations or data. Use at your own risk.

About Us — FAQ

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Contact & corrections

RentalInvestCalc is an independent editorial project. Spot a data error or want a source added? Email 18999737@qq.com or read our About page. We publish estimates and guides, not tax, legal, or financial advice — always confirm figures with the county assessor and a licensed CPA or attorney.