Mortgage Constant

A rate calculated by dividing the periodic loan payment by the initial loan amount. The Mortgage (or Loan) Constant is often used as a tool to efficiently calculate loan payments and is represented as a percentage. For instance, a mortgage loan with an annual payment of $16,000 and an initial loan balance of $250,000 has a Mortgage Constant of 6.40%. In an interest only loan, this metric would be the same as the interest rate where with an amortizing loan this would be different because there are principal payments included as well. Lenders can use this to compare different loans and how quickly they get back their loan amount through regular payments.

Putting ‘Mortgage Constant’ in Context

Mini-Case: Oakwood Business Plaza in Houston, TX

Scenario:
Riverstone Capital Partners, a real estate private equity firm, has recently acquired Oakwood Business Plaza, a suburban office complex located in Houston, Texas. The property spans 120,000 square feet and is leased to a mix of professional service firms and small tech companies. The purchase price was $24 million, financed with a $16 million, 10-year fixed-rate mortgage at a 5% interest rate. The firm expects to achieve steady cash flows from the property while benefiting from modest rental growth due to Houston’s expanding business environment.

The Role of Mortgage Constant

When Riverstone Capital Partners evaluated their financing options for Oakwood Business Plaza, the Mortgage Constant became a key metric. The Mortgage Constant is a percentage that represents the ratio of the periodic loan payment to the initial loan amount. This metric allowed the firm to quickly understand the cost of servicing the debt relative to the size of the loan and compare different loan structures effectively.

Calculation of the Mortgage Constant

Consider the following loan details:

  • Loan Amount: $16,000,000
  • Interest Rate: 5% (annual, fixed)
  • Term: 10 years
  • Monthly Payment: $169,059

The annual loan payment is calculated as $169,059 × 12 = $2,028,708. The Mortgage Constant is then:

Mortgage Constant = (Annual Loan Payment ÷ Loan Amount) × 100

Mortgage Constant = ($2,028,708 ÷ $16,000,000) × 100 = 12.67%

At 12.67%, the Mortgage Constant helps Riverstone Capital Partners assess the debt service burden relative to the size of the loan.

Why Mortgage Constant Matters

  • Loan Comparisons: By calculating the Mortgage Constant, Riverstone Capital Partners could compare the effective cost of this loan to alternative financing options.
  • Cash Flow Planning: The constant provided insight into the debt service’s impact on cash flow, helping ensure the property’s Net Operating Income (NOI) could comfortably cover the debt payments.
  • Loan Structure Insights: Since this is a fully amortizing loan, the Mortgage Constant is higher than the interest rate due to the inclusion of principal payments. This ensures the loan is repaid in full by the end of the 10-year term.

Lessons for the Protagonist

By using the Mortgage Constant, Riverstone Capital Partners gained a clear understanding of the loan’s impact on cash flow and its competitiveness compared to other financing structures. This metric played a vital role in their decision to proceed with the 10-year fixed-rate mortgage, ensuring the financing aligned with the firm’s investment strategy and property performance expectations.


Click here to get this CRE Glossary in an eBook (PDF) format.