Debt Service Coverage Ratio Calculator
Calculate DSCR to assess business loan serviceability.
What this calculator does
This DSCR calculator measures whether income covers debt payments with room to spare. Enter net operating income and annual debt service, and it returns the debt service coverage ratio along with a table showing what NOI would be required at various coverage levels and how much buffer you currently hold.
A ratio of 1.0 means income exactly covers payments with nothing left for a bad month. That is why lenders require a cushion. DSCR is the single most important number in commercial underwriting, and it frequently determines loan size before loan-to-value ever becomes the constraint.
When to use it
Run it before applying for commercial financing, because it tells you the loan size you can realistically support. Working backward from your NOI at the lender's required ratio gives a maximum annual debt service, and from there a maximum loan — a far more useful starting point than asking for a number and being cut back.
It is also the number to monitor if you already have covenants. Checking DSCR quarterly rather than discovering a breach in an annual review gives you months to act. And it is the right tool for testing a downside: knowing NOI can fall 7 percent before breach makes the covenant a concrete risk rather than an abstract term.
Understanding the inputs
Net operating income is revenue less operating expenses, before interest, taxes, depreciation, and amortization. For a property, include a realistic vacancy allowance and a management fee even if you self-manage, because a lender will impute both. Understating operating expenses inflates NOI and produces a ratio the lender will not agree with.
Annual debt service is the total of twelve monthly payments, principal and interest, across all facilities being tested. Include any required reserve or escrow contributions if your loan documents count them. If you are testing a proposed loan, calculate the payment first, then bring the annual figure here.
How is this calculated?
DSCR = Net Operating Income / Total Debt Service. DSCR > 1.25 is typically required by lenders.
A worked example
A business generates $420,000 in net operating income against $310,000 of annual debt service, giving a DSCR of about 1.35. Against a 1.25 covenant, that is comfortable — the maximum debt service the covenant permits is $336,000, so there is $26,000 of headroom.
Expressed as tolerance rather than headroom, NOI could fall to $387,500 before breaching, a drop of roughly 7.7 percent. For a business with stable contracted revenue that is adequate. For one with cyclical demand, a single soft quarter could consume it, which is the argument for either a longer amortization or a smaller loan.
Limitations and assumptions
The ratio is a snapshot built on a single period, and lenders will normalize your NOI in ways you may not have anticipated — imputing management fees, adjusting for below-market rents, or adding a vacancy allowance. The DSCR your lender calculates is frequently lower than the one you calculate.
It also says nothing about timing within the year. A business with strong annual coverage can still miss a payment during a seasonal trough, since DSCR is an annual measure applied to monthly obligations. Nor does it capture capital expenditure, which is excluded from NOI but very much requires cash. Pair it with a monthly cash flow forecast before relying on the annual figure.
Common Questions
- What DSCR do lenders require?
- Most commercial lenders set a minimum of 1.20 to 1.25, meaning net operating income must exceed annual debt payments by 20 to 25 percent. Multifamily lending often accepts 1.20, commercial property tends toward 1.25, and riskier asset classes such as hospitality can require 1.35 or more.
- What goes into net operating income for this calculation?
- Revenue less operating expenses, before interest, taxes, depreciation, and amortization. For property, that means rental income less management, maintenance, insurance, property taxes, and a vacancy allowance. Debt service itself is excluded — including it would double-count the very thing the ratio is testing.
- Does debt service include principal or just interest?
- Both. Debt service is the full annual payment, principal plus interest, because that is the cash actually leaving the business. Some lenders also add required reserve contributions. This is what distinguishes DSCR from an interest coverage ratio, which looks only at interest and produces a much more flattering figure.
- What happens if I breach a DSCR covenant?
- Technically it is an event of default, even if every payment has been made on time. In practice lenders usually issue a waiver in exchange for a fee, additional collateral, or a cash sweep. But it hands the lender leverage over your business at exactly the moment you have least, so covenant headroom is worth protecting.
- How much can income fall before I breach?
- The buffer is straightforward to compute. At a DSCR of 1.35 against a 1.25 covenant, NOI can fall about 7 percent before you breach. That figure is more useful than the ratio itself, because it translates the covenant into a tolerance you can compare against your actual revenue volatility.
- How does DSCR determine how much I can borrow?
- Lenders work backward from it. Divide NOI by the required DSCR to get maximum annual debt service, then convert that into a loan amount at the offered rate and term. This frequently binds before loan-to-value does, which is why a strong appraisal does not always translate into the loan size you expected.
- Can I improve DSCR without paying down debt?
- Three ways. Raise NOI through revenue or expense reduction, which is slow but permanent. Extend the loan term, which lowers annual debt service immediately at the cost of more total interest. Or refinance at a better rate. Lenders generally view an NOI improvement as far more credible than a term extension.
- What is a global DSCR?
- It includes all the borrower's debt obligations, including personal ones, rather than just the property or business in question. Lenders to small businesses increasingly use it because a personal guarantee makes your other commitments relevant to their risk. It is usually a tougher test than the property-level ratio.
- Do lenders use current or projected NOI?
- Trailing twelve-month actuals, almost always, and they will normalize them. Projected NOI carries little weight in underwriting because it is unverifiable. For a value-add property with a credible plan, a lender may size to stabilized NOI while requiring reserves or holdbacks until the numbers actually materialize.