Debt service coverage ratio
The debt service coverage ratio (DSCR), also known as "debt coverage ratio" (DCR), is the ratio of operating income available to debt servicing for interest, principal and lease payments. It is a popular benchmark used in the measurement of an entity's (person or corporation) ability to produce enough cash to cover its debt (including lease) payments. The higher this ratio is, the easier it is to obtain a loan. The phrase is also used in commercial banking and may be expressed as a minimum ratio that is acceptable to a lender; it may be a loan condition. Breaching a DSCR covenant can, in some circumstances, be an act of default.
In corporate finance, DSCR refers to the amount of cash flow available to meet annual interest and principal payments on debt, including sinking fund payments.
In personal finance, DSCR refers to a ratio used by bank loan officers in determining debt servicing ability.
In commercial real estate finance, DSCR is the primary measure to determine if a property will be able to sustain its debt based on cash flow. In the late 1990s and early 2000s banks typically required a DSCR of at least 1.2, but more aggressive banks would accept lower ratios, a risky practice that contributed to the Financial crisis of 2007–2010. A DSCR over 1 means that (in theory, as calculated to bank standards and assumptions) the entity generates sufficient cash flow to pay its debt obligations. A DSCR below 1.0 indicates that there is not enough cash flow to cover loan payments. In certain industries where non-recourse project finance is used, a Debt Service Reserve Account is commonly used to ensure that loan repayment can be met even in periods with DSCR<1.0 
In general, it is calculated by:
To calculate an entity's debt coverage ratio, you first need to determine the entity's net operating income. To do this you must take the entity's total income and deduct any vacancy amounts and all operating expenses. Then take the net operating income and divide it by the property's annual debt service, which is the total amount of all interest and principal paid on all of the property's loans throughout the year.
If a property has a debt coverage ratio of less than one, the income that property generates is not enough to cover the mortgage payments and the property's operating expenses. A property with a debt coverage ratio of .8 only generates enough income to pay for 80 percent of the yearly debt payments. However, if a property has a debt coverage ratio of more than 1, the property does generate enough revenue to cover annual debt payments. For example, a property with a debt coverage ratio of 1.5 generates enough income to pay all of the annual debt expenses, all of the operating expenses and actually generates fifty percent more income than is required to pay these bills.
A DSCR of less than 1 would mean a negative cash flow. A DSCR of less than 1, say .95, would mean that there is only enough net operating income to cover 95% of annual debt payments. For example, in the context of personal finance, this would mean that the borrower would have to delve into his or her personal funds every month to keep the project afloat. Generally, lenders frown on a negative cash flow, but some allow it if the borrower has strong outside income.
Typically, most commercial banks require the ratio of 1.15–1.35 times (net operating income or NOI / annual debt service) to ensure cash flow sufficient to cover loan payments is available on an ongoing basis.
Let's say Mr. Jones is looking at an investment property with a net operating income of $36,000 and an annual debt service of $30,000. The debt coverage ratio for this property would be 1.2 and Mr. Jones would know the property generates 20 percent more than is required to pay the annual mortgage payment.
The Debt Service Ratio is also typically used to evaluate the quality of a portfolio of mortgages. For example, on June 19, 2008, a popular US rating agency, Standard & Poors, reported that it lowered its credit rating on several classes of pooled commercial mortgage pass-through certificates originally issued by Bank of America. The rating agency stated in a press release that it had lowered the credit ratings of four certificates in the Bank of America Commercial Mortgage Inc. 2005-1 series, stating that the downgrades "reflect the credit deterioration of the pool". They further go on to state that this downgrade resulted from the fact that eight specific loans in the pool have a debt service coverage (DSC) below 1.0x, or below one times.
The Debt Service Ratio, or debt service coverage, provides a useful indicator of financial strength. Standard & Poors reported that the total pool consisted, as of June 10, 2008, of 135 loans, with an aggregate trust balance of $2.052 billion. They indicate that there were, as of that date, eight loans with a DSC of lower than 1.0x. This means that the net funds coming in from rental of the commercial properties are not covering the mortgage costs. Now, since no one would make a loan like this initially, a financial analyst or informed investor will seek information on what the rate of deterioration of the DSC has been. You want to know not just what the DSC is at a particular point in time, but also how much it has changed from when the loan was last evaluated. The S&P press release tells us this. It indicates that of the eight loans which are "underwater", they have an average balance of $10.1 million, and an average decline in DSC of 38% since the loans were issued.
And there is still more. Since there are a total of 135 loans in the pool, and only eight of them are underwater, with a DSC of less than 1, the obvious question is: what is the total DSC of the entire pool of 135 loans? The Standard and Poors press release provides this number, indicating that the weighted average DSC for the entire pool is 1.76x, or 1.76 times. Again, this is just a snapshot now. The key question that DSC can help you answer, is this better or worse, from when all the loans in the pool were first made? The S&P press release provides this also, explaining that the original weighted average DSC for the entire pool of 135 loans was 1.66x, or 1.66 times.
In this way, the DSC (debt service coverage) ratio provides a way to assess the financial quality, and the associated risk level, of this pool of loans, and shows the surprising result that despite some loans experiencing DSC below 1, the overall DSC of the entire pool has improved, from 1.66 times to 1.76 times. This is pretty much what a good loan portfolio should look like, with DSC improving over time, as the loans are paid down, and a small percentage, in this case 6%, experiencing DSC ratios below one times, suggesting that for these loans, there may be trouble ahead.
And of course, just because the DSCR is less than 1 for some loans, this does not necessarily mean they will default.
Pre-Tax Provision Method
Income taxes present a special problem to DSCR calculation and interpretation. While, in concept, DSCR is the ratio of cash flow available for debt service to required debt service, in practice – because interest is a tax-deductible expense and principal is not – there is no one figure that represents an amount of cash generated from operations that is both fully available for debt service and the only cash available for debt service.
While Earnings Before Interest, Taxes, Depreciation and Amortization (EBITDA) is an appropriate measure of a company's ability to make interest-only payments (assuming that expected change in working capital is zero), EBIDA (without the "T") is a more appropriate indicator of a company's ability to make required principal payments. Ignoring these distinctions can lead to DSCR values that overstate or understate a company's debt service capacity. The Pre-Tax Provision Method provides a single ratio that expresses overall debt service capacity reliably given these challenges.
Debt Service Coverage Ratio as calculated using the Pre-Tax Provision Method answers the following question: How many times greater was the company's EBITDA than its critical EBITDA value, where critical EBITDA is that which just covers its Interest obligations + Principal obligations + Tax Expense assuming minimum sufficient income + Other necessary expenditures not treated as accounting expenses, like dividends and CAPEX.
The DSCR calculation under the Pre-Tax Provision Method is EBITDA / (Interest + Pre-tax Provision for Post-Tax Outlays), where Pre-tax Provision for Post-tax Outlays is the amount of pretax cash that must be set aside to meet required post-tax outlays, i.e., CPLTD + Unfinanced CAPEX + Dividends. The provision can be calculated as follows:
If noncash expenses (depreciation + depletion + amortization) > post-tax outlays, then Pretax provision for post-tax outlays = Post-tax outlays
For example, if a company's post-tax outlays consist of CPLTD of $90M and $10M in unfinanced CAPEX, and its noncash expenses are $100M, then the company can apply $100M of cash inflow from operations to post-tax outlays without paying taxes on that $100M cash inflow. In this case, the pretax cash that the borrower must set aside for post-tax outlays would simply be $100M.
If post-tax outlays > noncash expenses, then Pretax provision for post-tax outlays = Noncash expenses + (post-tax outlays - noncash expenses) / (1- income tax rate)
For example, if post-tax outlays consist of CPLTD of $100M and noncash expenses are $50M, then the borrower can apply $50M of cash inflow from operations directly against $50M of post-tax outlays without paying taxes on that $50M inflow, but the company must set aside $77M (assuming a 35% income tax rate) to meet the remaining $50M of post-tax outlays. This company's pretax provision for post-tax outlays = $50M + $77M = $127M. 
- DSCR finance term by the Free Online Dictionary
- Corality Debt Service Coverage Ratio Tutorial
- Debt-Service Coverage Ratio (DSCR) on Investopedia
- "Andrukonis, David (May, 2013). "Pitfalls in ConventionalEarnings-Based DSCR Measures — and a Recommended Alternative". The RMA Journal". Archived from the original on 2013-06-16. Retrieved 2013-05-23.