About the Investment Property Analyzer
The Investment Property Analyzer underwrites a rental deal end-to-end: cap rate, NOI, cash-on-cash return, gross rent multiplier, debt service coverage ratio, and a 10-year cash-flow projection with appreciation, rent growth, and refinance modeling. Toggle between buy-and-hold and full BRRRR mode (Buy, Rehab, Rent, Refinance, Repeat) to see how much capital you recycle at the cash-out refi. The deal grade (A–F) is calibrated against market-class benchmarks — the same number is a great deal in Cleveland and a terrible one in San Francisco.
It is built for first-time investors comparing two shortlisted properties before making an offer, BRRRR operators stress-testing the refinance assumption, syndicators producing investor-facing pro formas, and house hackers running the numbers on owner-occupy duplexes.
All modeling runs locally in JavaScript. Purchase price, rent, expense assumptions, financing terms, and your deal addresses (if you type them) never leave the device — no broker lead capture, no analytics call, no cookie storing the underwriting. Deal terms are competitively sensitive in active markets; the analyzer deliberately keeps them client-side.
The most common way investors lose money on rentals is overestimating rent and underestimating expenses. Use real rent comps from Rentometer or local property managers, not Zillow Zestimates. Budget vacancy at 5–10% even in “hot” markets, and reserve 5–10% of rent each for maintenance and capex (HVAC, roof, appliances all have replacement cycles). The 50% rule (operating expenses ≈ 50% of gross rent ex-mortgage) is a sanity check — if your pro forma claims 25% expense ratio, you have missed something. Output is for planning only; never substitute for a CPA, attorney, and local market expertise before signing.
| Year | Property Value | Loan Balance | Equity | Annual NOI | Cash Flow | Cumulative Return |
|---|
How to Use the Investment Property Analyzer
Start by entering the purchase price of the property you are evaluating. Add rehab costs if you plan any renovations, then enter the after-repair value (ARV) — your best estimate of what the property will be worth once improvements are complete. Next, input your expected monthly rental income based on comparable rents in the area. Set a realistic vacancy rate, typically between 5% and 10% for stable markets, and enter your total monthly operating expenses excluding mortgage payments. Finally, dial in your financing terms: down payment percentage, interest rate, and loan term. Every metric updates instantly as you adjust inputs, so you can stress-test a deal by sliding vacancy up or tweaking the purchase price until the numbers work.
Understanding Cash-on-Cash Return vs Cap Rate
These two metrics answer different questions and serve different purposes. Cap rate (capitalization rate) measures the return on a property independent of how it is financed. It is calculated as annual net operating income divided by the property value. Cap rate lets you compare deals on a level playing field — a 7% cap rate property in Memphis can be directly compared to a 5% cap rate property in Denver regardless of loan terms. Cash-on-cash return, on the other hand, measures the return on your actual cash invested. It accounts for leverage: the down payment, closing costs, and rehab spending you put in. A property with a modest 5% cap rate can deliver a 12%+ cash-on-cash return with favorable financing because leverage amplifies returns. Experienced investors track both numbers — cap rate to evaluate the asset, cash-on-cash to evaluate the deal.
The BRRRR Strategy Explained
BRRRR stands for Buy, Rehab, Rent, Refinance, Repeat. The strategy works by purchasing undervalued properties, renovating them to increase value, renting them out, then refinancing at the new higher appraised value. If the after-repair value is high enough relative to your all-in cost, the refinance can return most or all of your original capital. That recycled capital goes into the next deal, allowing investors to scale a portfolio without needing fresh capital for every purchase. The key metric in BRRRR is the capital recycled percentage — ideally 100% or higher, meaning you pull all your money back out while keeping a cash-flowing asset. This tool models the entire refinance scenario at 75% LTV so you can see exactly how much capital stays trapped in the deal before you commit.
Why Vacancy Rate Matters More Than You Think
New investors consistently underestimate vacancy. Even in strong rental markets, turnover between tenants creates gaps: cleaning, repairs, listing, showing, screening, and lease signing can easily consume four to six weeks. A single extended vacancy in a year can erase two or three months of positive cash flow. The vacancy rate input in this tool reduces your effective gross income before any other calculation, so it directly impacts NOI, cap rate, and cash-on-cash return. Conservative investors model 8–10% vacancy even in tight markets. If you are investing in a college town with seasonal demand or a market with high renter turnover, 12–15% is more realistic. Run the analysis at multiple vacancy assumptions to see how sensitive your returns are to empty months.
The 1% Rule and Other Quick Screening Tests
The 1% rule states that a rental property’s monthly rent should equal at least 1% of the purchase price. A $200,000 property should rent for at least $2,000 per month. This is a screening heuristic, not a final analysis — it filters out obviously bad deals before you invest time in detailed underwriting. The gross rent multiplier (GRM) is the inverse: purchase price divided by annual rent. A GRM below 10 generally indicates a property worth analyzing further. Neither metric accounts for operating expenses, vacancy, or financing, which is why you need a tool like this one to run the complete picture. Properties that pass the 1% rule can still be poor investments if operating costs are high, and properties that fail it can work in markets with strong appreciation.
Building a 10-Year Investment Thesis
Real estate returns compound over time through four channels: cash flow, principal paydown, appreciation, and tax benefits. Year one cash flow might be modest, but by year five the loan balance has decreased, rents have grown with inflation, and the property has appreciated. The 10-year projection table in this tool models all four drivers year by year so you can see how total equity builds over time. Many deals that look marginal in year one become excellent by year five once principal paydown and appreciation are factored in. This long-term perspective is what separates investors who build lasting wealth from those who chase the highest day-one cash flow. Use the appreciation rate input to stress-test different scenarios — even a 2% annual appreciation rate compounds meaningfully over a decade.
Looking for related tools? Try our Rental Profit Calculator for short-term rental analysis, our Mortgage Calculator for payment details, or explore all Home & Real Estate tools.
Frequently Asked Questions
What's a good cap rate for rental property?
Class A urban markets (Seattle, Denver, Boston): 4 to 6 percent. Class B suburban markets: 6 to 8 percent. Class C working-class markets: 8 to 12 percent. Small rural markets: 10+ percent. Higher cap rates usually come with higher risk (crime, vacancy, maintenance, tenant quality). Compare cap rate to 10-year Treasury plus a risk premium.
What is the 1% rule?
The 1% rule says monthly gross rent should equal at least 1 percent of purchase price. A 200,000 dollar property should rent for at least 2,000 per month. It's a quick screen, not a decision maker, and it's nearly impossible to hit in expensive markets (California, New York). In cheap markets (Midwest, South), the 2% rule is the better filter.
What's the difference between cap rate and cash-on-cash return?
Cap rate is NOI divided by purchase price, ignoring financing. Cash-on-cash return is annual cash flow divided by cash invested, including financing. Cap rate compares properties independent of how you pay; cash-on-cash shows the actual return on your invested dollars. Leverage amplifies cash-on-cash above cap rate when NOI yield exceeds mortgage rate.
How much should I budget for maintenance and capex?
Set aside 5 to 10 percent of rent for ongoing maintenance and another 5 to 10 percent for capital expenditure reserve (roof, HVAC, appliances, flooring replacement cycles). On a 1,500 dollar rent, that's 150 to 300 per month. Older properties and heavy-use tenants need higher reserves.
How does BRRRR work?
BRRRR stands for Buy, Rehab, Rent, Refinance, Repeat. You buy distressed property with cash or short-term financing, renovate to add value, rent it out to prove the cash flow, then refinance at 70 to 75 percent of the ARV to pull your capital back out. Done right, you end up with a cash-flowing rental and most or all of your original capital back.
