Mortgage Calculator for Rental Property

Reviewed by: David Chen, CFA | Real Estate Investment Analyst
Last Updated: October 2025

Analyze your investment potential with our mortgage calculator for rental property. Beyond standard P&I, this tool helps you estimate cash flow by factoring in rental income, vacancy rates, property management fees, and maintenance costs.

Rental Property Calculator

Property Price ($)

Down Payment ($)

Investment loans typically require 20-25% down.

Interest Rate (%)

Rates are usually higher for rentals.

Loan Term (Years)

Monthly Rental Income ($)

Projected gross rent.

Est. Monthly Expenses (Tax/Ins/HOA) ($)

Other Monthly Costs (Vacancy/Maint) ($)

Budget 5-10% of rent for repairs/vacancy.

Estimated Monthly Cash Flow

$0.00

Rent Income minus All Expenses

mortgage calculator for rental property Formula

Evaluating a rental property requires two key formulas: the standard mortgage payment and the Net Operating Income (NOI) or Cash Flow calculation.

1. P&I = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
2. Cash Flow = Rent – (P&I + Taxes + Insurance + HOA + Maintenance + Vacancy)

Source: Investopedia (Real Estate Cash Flow)

Variables

P&I: Principal and Interest (Debt Service).
Gross Rent: Total income before expenses.
OpEx: Operating Expenses (Taxes, Insurance, Repairs, Management).

Related Calculators

What is a Mortgage Calculator for Rental Property?

A mortgage calculator for rental property differs from a standard home loan tool because it focuses on profitability. While a homeowner cares about affordability, an investor cares about Cash Flow.

This tool accounts for higher interest rates (investment loans typically carry a 0.5% – 1.0% premium over primary residence loans) and helps you determine if the rental income will cover the debt service plus operating costs.

How to Calculate Rental Property Profit (Example)

Purchase: $350,000 price, 25% down ($87,500). Loan: $262,500.
Debt Service: At 7.5% over 30 years, P&I is ~$1,835/mo.
Expenses: Taxes/Ins/HOA ($600) + Maintenance/Vacancy ($280) = $880.
Total Outflow: $1,835 + $880 = $2,715/mo.
Income: Rent is $2,900/mo.
Cash Flow: $2,900 – $2,715 = +$185/mo.

Frequently Asked Questions (FAQ)

What down payment is required for a rental property?

Most lenders require at least 20% to 25% down for investment properties to secure a conventional loan. FHA loans (3.5% down) are only possible if you live in one of the units (house hacking).

Can I use rental income to qualify?

Yes. Lenders typically allow you to use 75% of the projected rental income (appraisal) or actual lease income to offset the mortgage debt in your DTI ratio.

What is a good cash flow per door?

Many investors target $100 to $300 per month in positive cash flow per unit after all expenses and debt service, though this varies by market.

What is DSCR?

Debt Service Coverage Ratio. Lenders use this for investment loans. It’s Rent / PITI. A DSCR > 1.25 is usually preferred to ensure the property pays for itself.