Debt Capacity and Project Selection Under Leverage Limits

Why Positive NPV Does Not Guarantee Feasibility

A project can increase firm value on a standalone basis and still be impossible to finance within the firm’s borrowing limits. Lenders may restrict total debt relative to operating earnings, require a minimum interest-coverage ratio, or cap drawings under a credit commitment. Existing debt already uses part of the permitted capacity. The project-selection decision therefore has two distinct tests: does the project create value, and can the firm finance it without violating its constraints?

This tutorial uses a simplified covenant model to make those tests explicit. Net present values are treated as standalone project values, calculated using a rate appropriate to project risk. Financing constraints determine feasibility; they do not, by themselves, change a project’s operating NPV. If financing side effects such as fees or tax shields are material, they must be incorporated separately in the valuation.

Definition: Incremental debt capacity is the maximum additional borrowing that can be raised while satisfying the applicable debt limits and covenant tests. A project is financially feasible under a stated financing plan only if its required debt and equity funding are available and the resulting debt remains within that capacity.

A Simplified Debt-Capacity Model

Let $D_0$ be existing debt, $E$ be the EBITDA measure accepted for covenant purposes, $L$ be the maximum permitted debt-to-EBITDA ratio, $C$ be the minimum required EBITDA-to-interest ratio, and $r$ be the annual interest rate on debt. This model assumes the debt is interest-only for the coverage calculation, the rate is constant, and the covenant tests use the same stated EBITDA measure. Actual agreements can use different definitions, adjustments, and testing dates.

Under the leverage covenant, total debt cannot exceed $LE$. Under the coverage covenant, annual interest is $rD$ when total debt is $D$, and coverage must be at least $C$. A separate lender commitment may also limit total drawings. If the maximum total amount available under that commitment is $K$, then the total debt permitted by all three limits is the smallest of the three ceilings.

D_{\max}=\min\left(LE,\frac{E}{Cr},K\right)

The ratio $E/(Cr)$ follows from the coverage requirement $E/(rD)\geq C$. Because $E$, $C$, and $r$ are positive, multiplying both sides by $rD$ and dividing by $Cr$ gives $D\leq E/(Cr)$. The incremental capacity is not the total debt ceiling: existing debt must be subtracted.

B_{\max}=\max\left(0,D_{\max}-D_0\right)

The maximum with zero matters: if existing debt is already above a permitted ceiling, the formula does not create borrowing capacity. The firm may instead need to reduce debt or change its financing plan. This simplified calculation also assumes all three limits are expressed on a comparable total-debt basis; a commitment limit stated as undrawn availability must first be converted to the corresponding maximum total drawings.

Model condition: Use the covenant’s actual definitions and timing. A covenant based on EBIT rather than EBITDA, a floating borrowing rate, amortizing debt, or a commitment that excludes certain facilities can produce a different capacity. The equations above apply only under the stated simplified assumptions.

Worked Capacity and Feasibility Tests

Worked Example: A Positive-NPV Project at the Borrowing Limit

A hypothetical firm has existing debt of $24 million and covenant EBITDA of $12 million. Its maximum debt-to-EBITDA ratio is 3.0, minimum EBITDA-to-interest coverage is 4.0, the borrowing rate is 8% per year, and the lender’s total-drawings limit is $34 million. A project costs $14 million, has a standalone NPV of $2.2 million, and has $4 million of equity funding available for it. Determine feasibility under this funding plan.

Method. Calculate each total-debt ceiling first, take the smallest, and subtract existing debt.

The leverage ceiling is $3.0\times \$12=\$36$ million. The coverage ceiling is $\$12/(4.0\times0.08)=\$37.5$ million. The commitment ceiling is $34 million. Thus:

D_{\max}=\min(36,37.5,34)=\$34\text{ million}

Incremental debt capacity is $\$34-\$24=\$10$ million. After applying the $4 million of available equity, the project requires $\$14-\$4=\$10$ million of new debt. That exactly equals capacity, so the project is feasible under the stated plan. Its $2.2 million standalone NPV is positive, but feasibility comes from the funding test, not from the sign of NPV.

Check. Post-project debt is $34 million. Leverage is $34/12=2.8333$, below 3.0; coverage is $12/(0.08\times34)=4.4118$, above 4.0; and total drawings do not exceed $34 million.

Common mistake avoided: Subtracting the existing debt from just one covenant ceiling and ignoring the lender commitment would overstate capacity. The binding limit here is the $34 million commitment.

Worked Example: Choosing Between Projects Under Combined Funding Limits

A hypothetical firm has $20 million of existing debt and $10 million of covenant EBITDA. The leverage ceiling is 3.0, the coverage minimum is 4.0, the borrowing rate is 10% per year, and the total-drawings commitment is $30 million. The firm has $7 million of equity available for a set of indivisible projects. Project A costs $7 million and has NPV $1.4 million; Project B costs $9 million and has NPV $2.0 million; Project C costs $5 million and has NPV $0.9 million. Assume the projects’ operating NPVs are independent, and there are no interactions or additional financing costs. Which feasible combination has the greatest total NPV?

Method. First find the debt ceiling that binds, then test combinations against both the debt capacity and equity budget.

The leverage ceiling is $3.0\times \$10=\$30$ million. The coverage ceiling is $\$10/(4.0\times0.10)=\$25$ million, and the commitment ceiling is $30 million. Therefore total debt is capped at $25 million and incremental debt capacity is $\$25-\$20=\$5$ million.

The firm’s total funding available for projects is $7 million of equity plus $5 million of debt, or $12 million. Project A plus C costs $\$7+\$5=\$12$ million and can be funded: use $7 million of equity and $5 million of debt. Its combined NPV is $\$1.4+\$0.9=\$2.3$ million.

A plus B costs $16 million, and B plus C costs $14 million; neither fits the $12 million total funding limit. All three cost $21 million and are also infeasible. Each individual project fits the funding limit, with NPVs $1.4 million, $2.0 million, and $0.9 million respectively. The best feasible choice is therefore A plus C, with total NPV $2.3 million.

Check. The selected combination uses exactly $7 million of equity and $5 million of debt. Total debt becomes $25 million, so coverage is $10/(0.10\times25)=4.0$, exactly the required minimum; leverage is $25/10=2.5$, below 3.0.

Common mistake avoided: Selecting B simply because it has the highest individual NPV misses the value of the feasible A-plus-C combination. Conversely, adding all positive NPVs without checking the joint funding limits treats infeasible choices as available.

Worked Example: Project EBITDA and Pro Forma Capacity

A hypothetical firm has $25 million of existing debt and $10 million of current covenant EBITDA. Its maximum leverage ratio is 3.0, its minimum coverage ratio is 4.0, its borrowing rate is 10% per year, and it has no tighter commitment limit. Lenders permit stabilized project EBITDA to be included in the covenant calculation. Project X costs $8 million, adds $2.5 million of stabilized EBITDA, and has a standalone NPV of $1.6 million. The firm has $2 million of equity available. Determine whether it can fund X while meeting the covenants.

Method. Since the stated lender convention includes stabilized project EBITDA, calculate capacity using post-project EBITDA, then test the proposed debt draw. This convention must not be assumed when the loan documents do not permit it.

Pro forma EBITDA is $\$10+\$2.5=\$12.5$ million. The leverage ceiling is $3.0\times \$12.5=\$37.5$ million. The coverage ceiling is $\$12.5/(4.0\times0.10)=\$31.25$ million. The smaller ceiling is $31.25 million, so incremental capacity is $\$31.25-\$25=\$6.25$ million.

After using $2 million of equity, the project needs $\$8-\$2=\$6$ million of debt, which is within the $6.25 million capacity. Total debt would be $31 million. The resulting leverage ratio is $31/12.5=2.48$. Interest is $0.10\times31=\$3.1$ million, so coverage is $12.5/3.1=4.0323$. Both tests pass, and the project is feasible under the stated assumptions.

Check. The project’s positive $1.6 million NPV supports its value case; the separate covenant calculation confirms that the proposed financing fits. The headroom is only $0.25 million of debt capacity, so even a modest change to the accepted EBITDA, rate, or covenant terms could alter feasibility.

Common mistake avoided: Using current EBITDA of $10 million despite the explicit pro forma convention would give a different ceiling. The correct denominator depends on the lender’s covenant definition and permitted measurement date.

Applying the Test Systematically

A disciplined decision keeps valuation, financing, and feasibility distinct. Standalone NPV measures the project’s operating value under its stated cash flows and risk-matched discount rate. The debt-capacity calculation measures how much additional borrowing is permissible under the assumed covenants. Equity availability and any other funding sources determine whether the project’s total cost can actually be covered.

Specify the covenant basis.
Record existing debt, the accepted EBITDA measure, leverage ceiling, coverage minimum, borrowing rate, commitment limit, and whether projected project earnings count.

Compute total debt ceilings.
Calculate the leverage, coverage, and commitment limits using consistent units and the applicable measurement date.

Find incremental capacity.
Take the binding total-debt ceiling and subtract existing debt, with zero as the lower bound in this simplified model.

Test the financing plan.
Compare required project borrowing with capacity and verify that the remaining cost can be met with available equity or other permitted funds.

Rank feasible choices by value.
For independent projects with additive NPVs, compare total NPV only among combinations that satisfy the stated financing constraints.

The last step relies on explicit simplifications: projects are indivisible, their NPVs are additive, and there are no interactions or unmodeled financing effects. If projects depend on one another, affect each other’s cash flows, or change covenant measures in different ways, the feasible combinations and their values must be recalculated accordingly.

Interpretation and Common Traps

A binding covenant is the smallest applicable total-debt ceiling, not necessarily the leverage ratio. A firm may have ample leverage headroom but little coverage headroom, particularly when interest rates are high. Likewise, unused commitment availability is not automatically the same as covenant capacity: the firm must satisfy both the lender’s contractual drawing limit and any applicable financial tests.

Do not confuse a total ceiling with incremental borrowing. Subtract existing debt after finding the binding total-debt ceiling.
Do not assume positive NPV means financeable. A project can be valuable but exceed debt and equity resources available under the stated plan.
Do not treat debt limits as universal project vetoes. If additional equity or another permitted source is available, a project that cannot be funded with debt alone may still be feasible.
Do not count projected EBITDA without support. Use pro forma operating measures only when the stated covenant convention permits them.
Do not ignore the rate in a coverage test. Under this model, higher $r$ reduces the coverage-based debt ceiling $E/(Cr)$.

Key takeaway: Debt capacity is the minimum of the applicable total-debt limits, less existing debt. Use it as a financing constraint alongside—not as a substitute for—project NPV analysis. A positive-NPV project should be selected only when a feasible funding plan also satisfies the relevant limits.

Check Your Understanding

For each problem, use the simplified model stated in the question. Treat all dollar amounts as millions unless specified otherwise.

A firm has existing debt of $18, EBITDA of $9, a leverage ceiling of 2.5, a coverage minimum of 3.75, a borrowing rate of 8% per year, and a total-drawings limit of $26. A project requires $4.0 of new debt after equity funding. Find incremental capacity and determine feasibility. (Answer: Capacity is $4.5; the project is feasible with $0.5 of capacity remaining.)
A firm has existing debt of $12 and EBITDA of $6. Its leverage ceiling is 3.0, coverage minimum is 4.0, and borrowing rate is 10% per year. A $9 project has $5 of equity committed, with the balance to be debt-funded. Is it feasible? (Answer: Debt capacity is $3; the project needs $4 of debt and is infeasible by $1.)
A firm has existing debt of $30 and EBITDA of $15, a leverage ceiling of 2.5, a coverage minimum of 3.75, an 8% borrowing rate, and a commitment limit of $40 total. Project A needs $4 of debt and has NPV $1.1; Project B needs $5 of debt and has NPV $1.4. They are indivisible alternatives. Which alternative has the higher NPV while remaining feasible? (Answer: Capacity is $7.5; both are feasible, and choose B with NPV $1.4.)
A firm has existing debt of $16 and EBITDA of $8, a leverage ceiling of 3.0, a coverage minimum of 4.5, an 8% borrowing rate, and a $23 total-drawings limit. A project costs $10 and has $3 of equity available. Find the binding debt limit and determine whether the project is financeable. (Answer: The coverage ceiling is $22.22 total debt, giving $6.22 of capacity; the project needs $7 of debt and is infeasible by about $0.78.)
A firm has existing debt of $20 and current EBITDA of $10. Its leverage ceiling is 2.8, coverage minimum is 4.5, borrowing rate is 8%, and the lender’s total-drawings limit is $28. A project adds $1 of stabilized EBITDA that the lender permits in covenant calculations. The project costs $10, and $2 of equity is available. Find post-project incremental debt capacity and test the funding plan. (Answer: Post-project capacity is $8; the project needs $8 of debt and is feasible exactly at the limit.)

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