Commercial Loan DSCR Calculator Formula

Understand the math behind the commercial loan dscr calculator. Each variable explained with a worked example.

Use the Commercial Loan DSCR Calculator

Formulas Used

DSCR

debt_service_coverage = dscr

Annual Debt Service

annual_ds = annual_debt_service

Monthly Debt Service

monthly_ds = monthly_payment

Cash Flow After Debt Service

cash_after_debt = net_operating_income - annual_debt_service

Max Debt Service at 1.25x DSCR

max_ds_at_125 = max_debt_service

Breakeven Occupancy (approx)

breakeven_occ = net_operating_income > 0 ? (annual_debt_service / net_operating_income) * 100 : 0

Variables

VariableDescriptionDefault
net_operating_incomeNet Operating Income (NOI)(USD)180000
loan_amountLoan Amount(USD)1500000
interest_rateAnnual Interest Rate(%)6.5
amortization_yearsAmortization Period (years)25
loan_term_yearsLoan Term (years)10
monthly_rateDerived value= interest_rate / 100 / 12calculated
amort_paymentsDerived value= amortization_years * 12calculated
monthly_paymentDerived value= monthly_rate > 0 ? loan_amount * monthly_rate * pow(1 + monthly_rate, amort_payments) / (pow(1 + monthly_rate, amort_payments) - 1) : loan_amount / amort_paymentscalculated
annual_debt_serviceDerived value= monthly_payment * 12calculated
dscrDerived value= annual_debt_service > 0 ? net_operating_income / annual_debt_service : 0calculated
max_debt_serviceDerived value= net_operating_income / 1.25calculated

How It Works

Debt Service Coverage Ratio (DSCR)

DSCR is the most important metric lenders use to evaluate commercial real estate loan applications. It measures whether the property generates enough income to cover its debt payments.

Formula

DSCR = Net Operating Income / Annual Debt Service

Lender Requirements

  • Minimum 1.20x: Most conventional lenders require at least 1.20-1.25x
  • 1.25x-1.35x: Standard for most commercial loans
  • 1.40x+: Required for riskier property types or economic conditions
  • Below 1.0x: The property cannot cover its debt payments from income

    • Impact on Loan Amount

    Lenders work backward from DSCR to determine the maximum loan amount: 1. Start with the NOI 2. Divide by the required DSCR to find maximum allowable debt service 3. Calculate the loan amount that produces that debt service

    Amortization vs. Term

  • Amortization determines the payment amount (longer = lower payments)
  • Term is when the remaining balance is due (balloon payment)
  • Most commercial loans have 25-30 year amortization but 5-10 year terms

    • Worked Example

    $180,000 NOI, $1,500,000 loan at 6.5% interest, 25-year amortization, 10-year term.

    net_operating_income = 180000loan_amount = 1500000interest_rate = 6.5amortization_years = 25loan_term_years = 10
    1. 01Monthly payment: approximately $10,133 (25-year amortization at 6.5%)
    2. 02Annual debt service: $10,133 x 12 = $121,596
    3. 03DSCR: $180,000 / $121,596 = 1.48x
    4. 04Cash flow after debt: $180,000 - $121,596 = $58,404
    5. 05Max debt service at 1.25x: $180,000 / 1.25 = $144,000
    6. 06DSCR of 1.48x exceeds the typical 1.25x requirement

    Frequently Asked Questions

    What DSCR do lenders require?

    Most conventional commercial lenders require a DSCR of 1.20x to 1.35x. SBA loans typically require 1.15x to 1.25x. Life insurance companies and CMBS lenders usually require 1.25x or higher. The required DSCR depends on the property type, market, and economic conditions.

    How does DSCR affect my loan amount?

    A higher required DSCR means a lower maximum loan amount. If your NOI is $180,000 and the lender requires 1.25x, your maximum annual debt service is $144,000. The loan amount that produces $144,000 in annual payments depends on the rate and amortization period.

    What happens if DSCR drops below 1.0?

    A DSCR below 1.0 means the property does not generate enough income to cover debt payments. This may trigger a loan default, require the borrower to bring additional funds, or activate cash sweep provisions. It is a serious situation that requires immediate attention.

    Ready to run the numbers?

    Open Commercial Loan DSCR Calculator