What this rental property calculator shows you
Will It Flow is built as a real estate investment calculator: one workspace for the metrics below, plus saved deals and exports when you upgrade.
Monthly cash flow
After operating expenses and debt service — the number that hits your bank account each month (pre-tax).
Cap rate
Unleveraged yield from operations: NOI ÷ value. Useful for comparing properties regardless of financing.
DSCR
Debt service coverage — NOI ÷ annual debt service. A go-to screen for rental loans that qualify the asset.
Cash-on-cash return
Leveraged return on the cash you deployed: after-debt cash flow ÷ equity invested.
Net operating income
Rent less vacancy, less operating expenses — before mortgage principal and interest.
Mortgage payment
Principal and interest on your loan; the preview below can derive annual debt service from loan inputs and live-rate-based estimates.
Operating expenses
Taxes, insurance, maintenance, management, HOA, utilities you cover, and reserves — modeled line by line in the full app.
Long-term return
Multi-year equity buildup, appreciation (if you choose to model it), and IRR-style views on Invest when you want depth beyond a snapshot.
How to analyze a rental property
- Enter purchase price and financing — down payment, loan amount, rate, and term set your debt service and cash invested.
- Add rent and income assumptions — contract rent today, plus any other income you rely on (e.g. storage or parking) if it is durable.
- Estimate vacancy and operating expenses — use your market, insurer quotes, and a realistic repair reserve rather than best-case numbers.
- Review cash flow and return metrics — tie NOI to cap rate, after-debt cash flow to cash-on-cash, and NOI to debt to DSCR.
- Stress test before you offer — raise vacancy, lift rates, or trim rent and confirm the deal still clears your hurdle. Our rental property analysis checklist walks the same sequence.
Expenses to include
- Property taxes
- Insurance
- Repairs and maintenance (include a reserve, not just turnover)
- Property management — even if you self-manage today, buyers often underwrite a fee
- Vacancy and collection loss
- Utilities if you pay them as the landlord
- HOA dues if applicable
- Capital expenditures — roof, HVAC, and exterior work over your hold period
Example rental property calculation
This example is illustrative only — plug your own purchase price, rent roll, and expense lines into the preview above or into Will It Flow.
- Gross rent: $24,000/year ($2,000/month)
- Vacancy (5%): $1,200 → effective gross income $22,800
- Operating expenses: $8,000/year (taxes, insurance, maintenance, PM, etc.)
- NOI: $22,800 − $8,000 = $14,800/year
- Debt service: $12,000/year ($1,000/month P&I)
- Pre-tax cash flow: $14,800 − $12,000 = $2,800/year ( about $233/month before income taxes and optional reserves)
- DSCR: $14,800 ÷ $12,000 ≈ 1.23 — near a common 1.25 lender benchmark, but every program differs.
Benchmarks (rules of thumb, not promises)
- Positive cash flow is often preferred for buy-and-hold, but some investors accept early negative carry for appreciation or value-add — your strategy sets the bar.
- DSCR around 1.20 to 1.25 is a frequent lender talking point for non-owner-occupied rental loans; weaker ratios can still price, with worse terms or more reserves.
- Cap rate varies widely by market, asset class, and tenant risk — compare against other deals you can actually buy, not a national headline number.
- Cash-on-cash return moves with down payment, rate, and hold period; use it alongside cap rate and DSCR, not instead of them. See cap rate vs. cash-on-cash return and what is a good cash-on-cash return.
Why use Will It Flow instead of a spreadsheet?
- Faster deal analysis — structured inputs and instant outputs instead of rebuilding tabs for every offer.
- Saved assumptions — revisit deals without hunting for the last version of your workbook.
- Rent comps and market data — anchor rent and expense guesses to real listings and metro trends when you use the full app.
- Live mortgage rate context — the preview above can use PMMS-based investor spreads similar to our other calculators; the app keeps financing in sync with what you model.
- AI Deal Interpretation (Invest) — narrative read on the metrics you already calculated, not a black-box replacement for your underwriting.
- PDF deal sheets (Invest) — export a clean summary for partners or lenders.
Frequently asked questions
What is a rental property calculator?
A rental property calculator helps you estimate how a buy-and-hold investment performs before you make an offer. You enter purchase price and financing, rent and other income, vacancy, and operating expenses, then review cash flow and return metrics like DSCR, cap rate, and cash-on-cash return.
How do you calculate rental property cash flow?
Start with gross rent, subtract a vacancy allowance, then subtract operating expenses to get net operating income (NOI). Subtract your full mortgage payment (principal and interest) and any owner-paid utilities or reserves you want to model. What remains is your pre-tax cash flow before depreciation and income taxes.
What expenses should I include?
At minimum, model property taxes, insurance, repairs and maintenance, property management, vacancy, utilities you pay as the landlord, HOA dues if applicable, and a capital expenditure reserve. In Will It Flow you can tune each line and save assumptions across deals.
What is a good cash-on-cash return?
Cash-on-cash depends on your market, financing, and goals. Many long-term investors treat roughly 8–12% as strong for stabilized residential rentals, but lower can still work for appreciation-heavy markets. Use the same definition consistently (cash flow after debt divided by cash invested) when comparing deals.
What is a good DSCR for a rental property?
Many DSCR lenders look for roughly 1.20 to 1.25 or higher, but programs and pricing vary. Below 1.0 means NOI does not cover debt service out of operations. Use the free DSCR preview on this page, then stress rent and expenses before you lock a rate.
Is cap rate the same as cash-on-cash return?
No. Cap rate is unleveraged — annual NOI divided by property value. Cash-on-cash is leveraged — annual cash flow after debt divided by cash invested. They answer different questions; we unpack the comparison in our cap rate vs. cash-on-cash article.
Can this calculator be used for BRRRR deals?
The preview on this page focuses on stabilized rent, NOI, and debt service (ideal for DSCR-style screening). For full BRRRR — rehab budget, ARV, and refinance recovery — use our dedicated BRRRR calculator, then bring the stabilized deal into Will It Flow for saved scenarios and exports.
Related tools & guides
- DSCR calculator — standalone page with deeper lender context.
- Cap rate calculator — quick unleveraged yield check.
- All calculators — BRRRR, mortgage payment, 1% rule, and more.
- Housing market data — metros and trends for context around your assumptions.
- Rental property analysis checklist
- Cap rate vs. cash-on-cash return
- What is a good cash-on-cash return?
Run the full rental property calculator in Will It Flow
Cash flow, cap rate, DSCR, cash-on-cash, mortgage payment, expenses, and long-term returns in one workspace — with saved deals, comps-friendly rent inputs, and optional PDF and AI on Invest.
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