Rental Property Calculator

How to use

1. 1Pick a preset to seed realistic inputs (single family, duplex, all cash, house hack, short term), then edit any number to match the deal you are analyzing.
2. 2Enter purchase price, closing costs, rehab, down payment (percent or dollars), interest rate, and loan term. Use 0% interest for an all-cash purchase.
3. 3Add gross monthly rent and a vacancy allowance (5 to 8% for long term, 20 to 40% for short term), then fill in the operating expenses.
4. 4Read the result panel for monthly cash flow, cap rate, cash-on-cash return, NOI, GRM, 1% rule check, DSCR, and break-even occupancy.
5. 5Use the inline copy buttons or Copy summary to paste a clean breakdown into a deal memo, spreadsheet, or partner email.

About this tool

Rental Property Calculator turns a purchase price, financing terms, and a rent and expense ledger into every ratio rental investors actually look up: net operating income (NOI), cap rate, monthly and annual cash flow, cash-on-cash return on the dollars invested, gross rent multiplier (GRM), the classic 1% rule check, the 50% rule sanity check, debt service coverage ratio (DSCR) for lenders, and the break-even occupancy rate at which annual cash flow lands on zero. Enter the purchase price, closing costs, any up-front rehab, the down payment as a percent or a dollar amount, the loan interest rate, and the term in years. Add gross monthly rent, any other monthly income (parking, laundry, pet rent, storage), and a vacancy allowance, then the operating expenses: property tax per year, insurance per year, HOA per month, maintenance and capital expenditure reserves as a percent of rent, property management as a percent of rent (set 0 if you self-manage), utilities paid by the landlord, and any other monthly expense. Every number is computed with the textbook formulas: NOI is effective income minus operating expenses, cap rate is NOI divided by purchase price, cash-on-cash is annual pre-tax cash flow divided by total cash invested, GRM is purchase price divided by annual gross rent, and DSCR is NOI divided by annual debt service. NOI deliberately excludes the mortgage payment so the cap rate stays comparable across deals regardless of how each one is financed. Five built-in presets cover the most-searched scenarios in one click: a single family long-term rental, a small multifamily duplex, an all-cash purchase that isolates the cap rate from financing decisions, a house hack with FHA-style low down payment, and a short-term rental with higher rent, higher vacancy, and owner-paid utilities. The result panel highlights monthly cash flow in green when positive and red when negative, exposes a copy button on every ratio, and offers a one-click Copy summary that pastes a clean text block into a spreadsheet, deal memo, or partner email. Display currency switches between US Dollar, Euro, British Pound, Canadian Dollar, Australian Dollar, Indian Rupee, and Turkish Lira; no FX conversion is performed because nothing is uploaded. Useful for buy-and-hold investors screening a Zillow listing, BiggerPockets style deal analysis, a BRRRR refinance check, a rental syndication first-look, comparing two duplex offers, or for a future homeowner deciding whether to rent out the basement. The calculator models cash flow only; it does not project appreciation, depreciation, taxes, rent growth, or future capex events, so the page is honest about what it does and does not include. Every calculation runs entirely in your browser using deterministic IEEE 754 arithmetic, so purchase prices, rents, and expense numbers never leave your device.

Free to use. Works in your browser. No signup, no login.