Real Estate Calculator
Data-driven analysis for smarter property investments.
1. Acquisition Costs
2. Monthly Income & Expenses
Real Estate Calculator
Thinking about buying an investment property? Run the numbers first. This real estate calculator shows you cap rate, cash flow, and return on investment so you can evaluate any deal before you commit.
What Does This Calculator Cover?
It calculates the key metrics every real estate investor needs: Net Operating Income (NOI), cap rate, cash-on-cash return, and annual cash flow — all from a few simple inputs.
How to Use This Calculator
- Enter the purchase price of the property.
- Enter your down payment and estimated mortgage payment.
- Enter total monthly rental income.
- Enter monthly operating expenses: taxes, insurance, maintenance, vacancy, property management.
- Click Calculate to see your investment metrics.
Key Formulas
NOI = Annual Rental Income − Annual Operating Expenses
Cap Rate = NOI ÷ Property Value × 100
Cash-on-Cash Return = Annual Cash Flow ÷ Total Cash Invested × 100
Annual Cash Flow = NOI − Annual Mortgage Payments
Example Calculation
Purchase price: $300,000 | Down payment: $60,000 | Monthly rent: $2,400 | Monthly expenses: $800 | Monthly mortgage: $1,200
- Annual income: $28,800 | Annual expenses: $9,600
- NOI: $19,200
- Cap Rate: $19,200 ÷ $300,000 = 6.4%
- Annual cash flow: $19,200 − $14,400 = $4,800
- Cash-on-cash: $4,800 ÷ $60,000 = 8%
What Is a Good Cap Rate?
A cap rate of 5%–10% is generally considered good, but it varies by market. High-cost cities like NYC or SF often see cap rates of 2%–4%, while midwestern markets may offer 8%–12%.
Common Mistakes to Avoid
- Underestimating vacancy — Budget for 5%–10% vacancy rate; units won't always be occupied.
- Forgetting capital expenditures — Roofs, HVAC, and appliances fail. Reserve 5%–10% of rent for future repairs.
- Using gross income without deducting expenses — Never use gross rent yield as your sole metric.
- Ignoring property management costs — If you hire a manager, budget 8%–12% of rent.
Frequently Asked Questions
What is the 1% rule in real estate?
The 1% rule says your monthly rent should equal at least 1% of the purchase price. A $300,000 property should rent for at least $3,000/month. It's a quick screening tool, not a full analysis.
How is cap rate different from ROI?
Cap rate ignores financing and measures property income relative to its value. ROI (or cash-on-cash return) accounts for your actual cash invested after the mortgage, giving a truer picture of your personal return.
Should I use a property manager?
Property managers save time but cost 8%–12% of rent. If you have multiple properties or live far from the rental, a manager often pays for itself in stress reduction and professional tenant screening.
How do I account for appreciation?
Historical US home appreciation averages 3%–4% annually, but it varies widely by market. Add expected appreciation to your total return calculation for a complete picture.
What other calculators should I use?
See our Rental Property Calculator for a deeper analysis, or our Mortgage Calculator to estimate your loan payment.
Conclusion
Never buy an investment property based on gut feeling alone. Run every deal through this calculator first. A few minutes of number-crunching can save you from a costly mistake — or confirm that you've found a great opportunity.
Related: Rental Property Calculator | Mortgage Calculator | ROI Calculator | Investment Calculator
Expert Tip
Always verify local property tax rates as they vary significantly by county. A $100/month difference can swing an investment from positive to negative cash flow.
