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Long-Term Rentals

Rental Underwriting Model

The full buy-and-hold analysis: effective income after vacancy, honest operating expenses, debt service, and the two headline metrics — cash-on-cash return and cap rate — in one view. This is the model Austin runs on every long-term Indianapolis deal before making an offer.

Best for

  • Buy-and-hold investors analyzing a specific property
  • Buyers comparing two or three finalist deals head-to-head
  • Anyone who wants to know what a property earns, not what it costs

Use it when

  • After a listing passes your initial 1% rule screen
  • Before making an offer, to set your walk-away price
  • When a lender or partner asks what the deal yields

Run your numbers

Every figure updates as you type — the defaults are typical Indianapolis numbers.

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The full underwrite

Effective monthly rent$1,488
Monthly operating expenses$510
Net operating income (mo)$978
Monthly cash flow-$86
Annual cash flow-$1,032
Cash-on-cash return-1.9%
Cap rate5.9%
Total cash invested$54,000

Indianapolis benchmarks

6–9%

Cap rate range many Indianapolis rentals are producing in 2026

8–12%

Cash-on-cash return most investors target after debt service

5–8%

Vacancy assumption Indianapolis investors build in

35–50%

Operating expenses as a share of effective gross income (reserves included)

The math behind this calculator

Every number in the tool above comes from these formulas — nothing hidden.

Effective gross income

EGI = (gross rent + other income) × (1 − vacancy rate)

Other income is everything from pet rent to utility bill-backs. Vacancy turns the paper rent into the rent you actually collect.

Net operating income

NOI = EGI − operating expenses

Operating expenses never include the mortgage payment — NOI is the property’s earning power before financing, which is why lenders and appraisers live by it.

Cap rate

Cap rate = NOI ÷ purchase price (or total project cost)

The unlevered return: what the property earns on its price if you paid all cash. It lets you compare deals across prices and neighborhoods on equal footing.

Annual cash flow

Cash flow = NOI − annual debt service

Debt service is principal and interest only — taxes and insurance already sit in operating expenses above.

Cash-on-cash return

Cash-on-cash = annual pre-tax cash flow ÷ total cash invested

Cash invested includes down payment, closing costs, and rehab — everything that left your account to own the deal. This is the return on your actual dollars.

Underwrite the property, not the story

Every listing comes with a story: "motivated seller," "rents below market," "just needs paint." Underwriting is the discipline of replacing the story with arithmetic. The model answers exactly one question — what does this property do at realistic rents and honest expenses? — and it answers it before you’ve spent a dollar or fallen in love.

The sequence never changes: effective income, then operating expenses, then NOI, then debt, then cash-on-cash. Deals that fail usually fail at the same two places — income that was never real, and expenses that were never counted. This model makes you write both down.

From gross rent to effective income

Gross potential rent is the number in the listing. Effective income is what’s left after vacancy — 5–8% is the standard assumption for Indianapolis single-family rentals. A single vacancy month on a 12-month lease costs 8.3% of annual income all by itself; the 5–8% band simply assumes you won’t re-lease instantly every time.

Add other income honestly: pet rent, late fees, utility bill-backs, and storage all count and they’re often the difference between a thin deal and a workable one. Then verify the rent itself — three genuine comparables within a mile at the same beds, baths, and condition. A $100 overestimate compounds into a 6–8% error in NOI and a full percentage point of phantom cap rate.

Honest expense benchmarks for Indianapolis

  • Maintenance plus capital reserves: 10–15% of collected rent combined. Much of Indy’s housing stock is pre-1970 — roofs, furnaces, galvanized plumbing, and knob-and-tube wiring don’t schedule themselves around your cash flow. The reserve is what makes a $6,000 roof a plan instead of a crisis.
  • Property management: 8–10% of collected rent plus lease-up fees if outsourced. If you self-manage, budget it anyway — that’s the market price of the job you’re doing, and it keeps the analysis honest enough to compare against hiring out.
  • Taxes and insurance: actual parcel taxes from the county auditor and a real insurance quote. Indiana reassessment after a sale can push taxes above the seller’s current bill — underwrite the post-sale figure, not the one in the listing.
  • The 50% rule as a sanity check: the old rule of thumb says operating expenses (including capital items) run about half of gross rent. It’s crude, but if your model shows expenses far below 50% of collected rent including reserves, you’ve probably forgotten a category.

The two headline metrics — and how leverage connects them

Cap rate is the unlevered return: NOI divided by price. Cash-on-cash is the levered return: cash flow divided by cash in. They measure the same property from two sides of the mortgage, and the gap between them is the entire effect of financing.

When debt costs less than the cap rate, leverage works for you: a 7% cap rate property financed at 6% produces a cash-on-cash above 7%. When debt costs more than the cap rate, leverage works against you — at an 8% interest rate that same property drags cash-on-cash under the cap. This is the mechanic that decides whether a mortgage helps or hurts, and why the same deal can be a yes at 6% financing and a no at 8%.

Indianapolis rentals in 2026 commonly pencil in the 6–9% cap rate range, with cash-flow neighborhoods at the top and premium suburbs at the bottom. Most investors target 8–12% cash-on-cash; below 6% needs a specific reason — an appreciation thesis, a 1031 deadline, or a documented value-add plan.

Value-add math that actually works

Rental value is capitalized income, which makes small rent gains surprisingly valuable. Raise NOI by $1,200 a year — a $100 monthly rent bump — and at a 7% cap rate you’ve created roughly $17,000 of value. Add a washer/dryer, finish a legal unit, or bill back utilities and the arithmetic repeats.

This is also the honest test of a "value-add opportunity" listing: if the claimed rent upside requires $20,000 of work to capture $50 of monthly rent, the value created barely covers the capital spent. Run the improvement through this model before paying the seller for their imagination.

Stress-test before you buy

  • Rents down 10% — does it still cash flow? Single-tenant properties carry concentrated risk.
  • Expenses up 10% — older homes will find ways to spend the difference.
  • One turnover per lease cycle — make-readies commonly run $1,000–$3,000 in paint, cleaning, and repairs.
  • A rate reset at refinance — if your loan isn’t fixed for the hold, rerun the deal at +1%.
  • If it only works with zero vacancy, zero maintenance, and best-case rents, it does not work.

Mistakes that show up in every bad deal

  • Using pro-forma rents the current owner never collected — verify against leases and deposit history.
  • Zero vacancy — Indianapolis averages 5–8% even in strong years.
  • No capital reserve — the single most common omission in amateur underwriting.
  • Trusting the seller’s expense sheet without checking the county auditor for taxes and an actual insurance quote.
  • Ignoring lease-up: the clock between closing and the first rent check is a real cost with a real price.

Common questions

What is a good cap rate in Indianapolis?

In 2026, many Indianapolis rentals produce roughly 6–9% cap rates depending on neighborhood, condition, and price point. Cash-flow neighborhoods on the east and south sides tend to run higher; premium areas like Carmel and Zionsville trade lower cap rates in exchange for appreciation and stability. A 6% cap on a new-ish suburban home and a 9% cap on a 1920s bungalow are different risk profiles, not different qualities of deal.

How is cash-on-cash different from cap rate?

Cap rate is the property’s return before financing (NOI ÷ price). Cash-on-cash is your return on the actual cash you invested after the mortgage (annual cash flow ÷ total invested). Cap rate compares properties; cash-on-cash tells you what your money earns. Leverage with debt cheaper than the cap rate raises cash-on-cash above the cap rate — expensive debt drags it below.

How reliable is the 50% rule?

It’s a screen, not an underwrite. The rule of thumb — operating expenses including capital items run about half of gross rent — catches wild underestimates fast, but real ratios swing from 35% on new construction to 60%+ on older homes with owner-paid utilities. Use it to sanity-check this model’s output, not to replace it.

How much should I hold in reserves per door?

A common floor is 3–6 months of full carrying cost (payment plus taxes, insurance, and HOA) per unit, separate from your rehab budget. The monthly capital reserve inside this model — part of your 10–15% maintenance-plus-capex band — builds the longer-term cushion for roofs, HVAC, and plumbing.

How do I verify the rent roll and expenses on a listed property?

Ask for current leases, 12 months of deposit ledgers or bank statements, and the last two years of tax bills — then cross-check taxes against the county auditor yourself. Look for rents only a related tenant would pay, and leases that expire the month after closing. If a seller won’t document income, underwrite it as zero.

Should I include management even if I self-manage?

Yes. The 8–10% is the market price of the work, and including it keeps two things honest: your return is comparable to any other investor’s, and you can see exactly what hiring a manager would cost the deal later. Many self-managers discover the discount isn’t worth the phone calls — the model lets you price that choice.

What is the 1% rule and should I use it?

The 1% rule says monthly rent should equal at least 1% of the purchase price. It’s a fast screen — many solid Indianapolis deals today run 0.6–0.9% and still cash flow well with honest expenses modeled. Use our Simple Pro Forma to screen quickly, then this model to underwrite the finalists properly.

These calculators are educational tools. Good underwriting still depends on accurate rents, expenses, financing, repairs, vacancy, management, and local market judgment.

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