Analyze your potential investment returns instantly.
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Gross Monthly Income:
Vacancy Loss:
Effective Operating Income:
Total Monthly Expenses:
Net Operating Income (Monthly):
Monthly Cash Flow:
Annual Cash Flow:
function calculateRentalCashFlow() {
// Retrieve inputs
var rent = parseFloat(document.getElementById('rcf_monthly_rent').value) || 0;
var otherIncome = parseFloat(document.getElementById('rcf_other_income').value) || 0;
var vacancyRate = parseFloat(document.getElementById('rcf_vacancy_rate').value) || 0;
var mgmtRate = parseFloat(document.getElementById('rcf_mgmt_fee').value) || 0;
var mortgage = parseFloat(document.getElementById('rcf_mortgage').value) || 0;
var annualTax = parseFloat(document.getElementById('rcf_annual_tax').value) || 0;
var annualIns = parseFloat(document.getElementById('rcf_annual_insurance').value) || 0;
var repairRate = parseFloat(document.getElementById('rcf_repair_rate').value) || 0;
var capexRate = parseFloat(document.getElementById('rcf_capex').value) || 0;
var hoa = parseFloat(document.getElementById('rcf_hoa').value) || 0;
// Calculations
var grossIncome = rent + otherIncome;
var vacancyLoss = grossIncome * (vacancyRate / 100);
var effectiveIncome = grossIncome – vacancyLoss;
var mgmtFee = effectiveIncome * (mgmtRate / 100);
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var repairs = grossIncome * (repairRate / 100); // Usually based on gross
var capex = grossIncome * (capexRate / 100); // Usually based on gross
var totalExpenses = mortgage + mgmtFee + monthlyTax + monthlyIns + repairs + capex + hoa;
var cashFlow = effectiveIncome – totalExpenses;
var annualCashFlow = cashFlow * 12;
// NOI excludes Mortgage Payment
var noi = (effectiveIncome – (totalExpenses – mortgage));
// Format Currency Helper
function formatMoney(num) {
return '$' + num.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
// Display Results
document.getElementById('rcf_results_area').style.display = 'block';
document.getElementById('rcf_res_gross').innerHTML = formatMoney(grossIncome);
document.getElementById('rcf_res_vacancy').innerHTML = '-' + formatMoney(vacancyLoss);
document.getElementById('rcf_res_effective').innerHTML = formatMoney(effectiveIncome);
document.getElementById('rcf_res_expenses').innerHTML = '-' + formatMoney(totalExpenses);
document.getElementById('rcf_res_noi').innerHTML = formatMoney(noi);
var cfEl = document.getElementById('rcf_res_cashflow');
cfEl.innerHTML = formatMoney(cashFlow);
cfEl.className = 'rcf-result-value ' + (cashFlow >= 0 ? 'rcf-positive' : 'rcf-negative');
var acfEl = document.getElementById('rcf_res_annual_cashflow');
acfEl.innerHTML = formatMoney(annualCashFlow);
acfEl.className = 'rcf-result-value ' + (annualCashFlow >= 0 ? 'rcf-positive' : 'rcf-negative');
}
How to Calculate Rental Property Cash Flow
Understanding cash flow is the cornerstone of successful real estate investing. Cash flow represents the net amount of cash moving in and out of a business. In real estate, positive cash flow means your property is generating more income than it costs to own and operate, resulting in passive income for you.
The Basic Formula
The simplified formula for rental property cash flow is:
Many new investors make the mistake of assuming a property will be rented 100% of the time and that nothing will break. This calculator includes specific fields for:
Vacancy Rate: A percentage (usually 5-8%) set aside to cover periods where the unit is empty between tenants.
CapEx (Capital Expenditures): Savings for major future replacements like a new roof, HVAC system, or water heater. Allocating 5-10% ensures you aren't bankrupted by a big repair bill.
Interpreting Your Results
Net Operating Income (NOI): This metric looks at the profitability of the property excluding the mortgage. It is useful for comparing the raw performance of different properties regardless of how they are financed.
Cash Flow: This is your "take-home" pay from the property. A rule of thumb for many investors is to seek at least $100-$200 per "door" (unit) in positive monthly cash flow, though this varies by market and appreciation goals.
Using this Rental Property Cash Flow Calculator helps you perform a "stress test" on your investment. Try increasing the interest rate or vacancy rate to see if the deal still makes sense in a market downturn.