Finance Quiz: Cost Of Debt
20 questions · exam conditions
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Cost Of DebtQuestion 1 of 20

A company's pre-tax cost of debt is 8.0%, and its after-tax cost of debt is 5.6%. What is the company's marginal tax rate?

2.4%
30.0%
42.9%
70.0%
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Finance Quiz

Finance Quiz: Cost Of Debt

Practice Cost Of Debt in Finance with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Cost Of Debt, giving you a quick way to practice the rules, question types, and explanations that matter most for Finance.

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Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

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Question 1

A company's pre-tax cost of debt is 8.0%, and its after-tax cost of debt is 5.6%. What is the company's marginal tax rate?

  1. 2.4%
  2. 30.0% (correct answer)
  3. 42.9%
  4. 70.0%
Explanation: The formula for the after-tax cost of debt is: After-Tax Cost = Pre-Tax Cost × (1 - Marginal Tax Rate). We can rearrange this to solve for the tax rate (t): 1 - t = After-Tax Cost / Pre-Tax Cost. Plugging in the given values: 1 - t = 5.6% / 8.0% = 0.70. Therefore, t = 1 - 0.70 = 0.30, or 30.0%.

Question 2

An analyst is estimating the cost of debt for a company with a credit rating of A. The yield on 10-year U.S. Treasury bonds is currently 3.5%. The typical credit spread for A-rated corporate bonds over the 10-year Treasury is 150 basis points. If the company's marginal tax rate is 22%, what is its estimated after-tax cost of debt?

  1. 2.73%
  2. 3.90% (correct answer)
  3. 5.00%
  4. 5.46%
Explanation: The pre-tax cost of debt can be estimated by adding the company's credit spread to the risk-free rate. 150 basis points is equal to 1.50%. Pre-tax cost of debt = Risk-free rate + Credit spread = 3.50% + 1.50% = 5.00%. The after-tax cost of debt is then calculated as: Pre-tax cost × (1 - Tax Rate) = 5.00% × (1 - 0.22) = 3.90%.

Question 3

A firm has existing debt issued five years ago with a 4% coupon rate. It is now considering a new project and will finance it with a new bond issuance. Current market conditions require the firm to offer a 7% coupon for a new bond issued at par. The firm's marginal tax rate is 21%. Which of the following is the most appropriate after-tax cost of debt to use when evaluating the new project?

  1. 3.16%
  2. 4.35%
  3. 5.53% (correct answer)
  4. 7.00%
Explanation: For capital budgeting decisions, the relevant cost of capital is the marginal cost, not the historical (or embedded) cost. The cost of the new debt issuance represents the marginal cost. Since the new bond will be issued at par with a 7% coupon, its yield to maturity (pre-tax cost of debt) is 7%. The after-tax cost is this marginal rate adjusted for taxes: 7.00% × (1 - 0.21) = 5.53%. The 4% coupon rate on old debt is irrelevant.

Question 4

An analyst is estimating the cost of debt for a company with no publicly traded bonds. The company has a bank loan with a fixed interest rate of 6.5%. The analyst determines the company's credit rating is equivalent to a BBB rating. The yield to maturity on publicly traded bonds for BBB-rated companies is currently 7.5%. The company's tax rate is 30%. What is the most appropriate after-tax cost of debt to use for this company's WACC?

  1. 4.55%
  2. 5.25% (correct answer)
  3. 6.50%
  4. 7.50%
Explanation: When debt is not publicly traded, the cost of debt should be estimated based on the yield of comparable publicly traded bonds. The interest rate on the existing bank loan represents a historical cost, not the current marginal cost. The yield on similarly rated (BBB) bonds, 7.5%, is the best estimate of the company's current pre-tax marginal cost of debt. Therefore, the after-tax cost of debt is 7.5% × (1 - 0.30) = 5.25%.

Question 5

An analyst reviewing a company's financial statements divides the reported interest expense from the income statement by the total debt on the balance sheet to estimate the cost of debt. This method is most likely to be an inaccurate estimate of the marginal cost of debt because it:

  1. fails to adjust for the company's marginal tax rate.
  2. ignores the cash flows to shareholders from dividend payments.
  3. uses the book value of equity instead of the market value of equity.
  4. reflects the historical, or embedded, cost of outstanding debt. (correct answer)
Explanation: When estimating a company's cost of debt for valuation or capital structure decisions, you need the marginal cost of debt—what it would cost to borrow additional funds today. This is crucial because companies use this rate for investment decisions and WACC calculations. The method described—dividing interest expense by total debt—gives you an average of what the company has paid historically on all its outstanding debt. This reflects the embedded cost of debt that was issued at different times under different market conditions. Some debt might have been issued years ago when interest rates were much higher or lower than today's rates. Answer D correctly identifies this fundamental flaw: the calculation reflects historical costs, not the current marginal borrowing rate. Let's examine why the other options miss the mark. A is incorrect because while tax adjustments matter for after-tax cost of debt, the question asks about estimating the cost of debt itself—the tax shield is a separate consideration. B is wrong because dividend payments to shareholders are irrelevant to debt costs; they're equity-related cash flows. C incorrectly focuses on equity valuation issues when the problem is purely about debt cost estimation—book versus market value of equity doesn't affect this particular calculation. Study tip: Remember that "marginal" in finance means "the next dollar" or "incremental." When you see questions about marginal cost of debt, ask yourself: "What would it cost to borrow today?" Historical averages rarely give you that forward-looking rate that decision-makers actually need.

Question 6

For a single bond issue, an analyst observes the following rates: Coupon Rate = 6.0%, Current Yield = 6.5%, and Yield to Maturity (YTM) = 7.0%. If the company's marginal tax rate is 30%, which of the following is the most appropriate after-tax cost of debt to include in a WACC calculation?

  1. 4.20%
  2. 4.55%
  3. 4.90% (correct answer)
  4. 7.00%
Explanation: The yield to maturity (YTM) is the most accurate measure of the market's required rate of return on a bond, as it considers the coupon payments, the final principal repayment, and the current market price. Therefore, the YTM is the correct pre-tax cost of debt. The after-tax cost of debt is calculated by applying the tax shield to the YTM: After-tax cost = YTM × (1 - Tax Rate) = 7.0% × (1 - 0.30) = 4.90%. The coupon rate and current yield are less complete measures of the cost of debt.

Question 7

A company's capital structure includes debt that has a market value of $200 million and a book value of $180 million. The debt's yield to maturity is 6.8%. The company's marginal tax rate is 25%. When calculating the weighted average cost of capital (WACC), the after-tax cost of debt component (k_d(1-t)) should be calculated as:

  1. 5.10%, using the yield to maturity. (correct answer)
  2. 5.78%, using an interest rate derived from book value.
  3. 6.80%, without adjusting for taxes.
  4. 4.50%, based on a different calculation method.
Explanation: The after-tax cost of debt is found by multiplying the pre-tax cost of debt by (1 - tax rate). The most appropriate measure for the pre-tax cost of debt is the current yield to maturity (YTM) on the company's debt, which is given as 6.8%. The book value and market value of debt are used for determining the weight of debt in the WACC, not for calculating the cost of debt itself. Therefore, the after-tax cost of debt is 6.8% × (1 - 0.25) = 5.10%.

Question 8

A 20-year, zero-coupon bond has a face value of $1,000 and currently trades at a market price of $300. The issuing corporation has a marginal tax rate of 40%. What is the after-tax cost of debt for this bond?

  1. 0.00%
  2. 3.72% (correct answer)
  3. 6.20%
  4. 8.00%
Explanation: The pre-tax cost of a zero-coupon bond is its yield to maturity (YTM). The YTM can be found by solving the formula: Price = Face Value / (1 + YTM)^N. Using a financial calculator: N = 20; PV = -$300; PMT = 0; FV = $1,000. Solving for I/Y gives a YTM of 6.20%. Although no cash interest is paid, the imputed interest (bond discount accretion) is typically tax-deductible for the issuer. Thus, the after-tax cost of debt is YTM × (1 - Tax Rate) = 6.20% × (1 - 0.40) = 3.72%.

Question 9

A corporation is planning to issue new 20-year bonds at their par value of $1,000. The bonds will have a 7% annual coupon. Flotation costs are expected to be 3% of the par value. If the corporation's marginal tax rate is 30%, what is the estimated after-tax cost of this new debt?

  1. 4.90%
  2. 5.11% (correct answer)
  3. 7.00%
  4. 7.30%
Explanation: The cost of new debt must account for flotation costs, which reduce the net proceeds from the bond issue. The net proceeds are the issue price minus flotation costs: $1,000 - (3% × $1,000) = 970.Thepre−taxcostofdebtistheyieldtomaturity(YTM)calculatedbasedonthesenetproceeds.Usingafinancialcalculator:N=20;PV=−970. The pre-tax cost of debt is the yield to maturity (YTM) calculated based on these net proceeds. Using a financial calculator: N = 20; PV = -970; PMT = $70; FV = $1,000. Solving for I/Y gives a YTM of 7.30%. The after-tax cost is YTM × (1 - Tax Rate) = 7.30% × (1 - 0.30) = 5.11%.

Question 10

A company has an outstanding bond with 10 years to maturity, a par value of $1,000, and an 8% semi-annual coupon. The bond's current market price is $1,100. If the company's marginal tax rate is 25%, what is its after-tax cost of debt?

  1. 4.85%
  2. 4.91% (correct answer)
  3. 6.00%
  4. 6.54%
Explanation: The after-tax cost of debt is the yield to maturity (YTM) adjusted for taxes. First, calculate the YTM. Since the bond pays a semi-annual coupon, the inputs for a financial calculator are: N = 10 × 2 = 20; PV = -1,100;PMT=(1,100; PMT = (1,000 × 8%) / 2 = $40; FV = $1,000. Solving for the interest rate gives a semi-annual yield (I/Y) of 3.27%. The annualized YTM is 3.27% × 2 = 6.54%. This is the pre-tax cost of debt. The after-tax cost of debt is YTM × (1 - Tax Rate) = 6.54% × (1 - 0.25) = 4.91%.

Question 11

A company has an outstanding bond with a face value of $1,000, 8 years to maturity, and a 7% annual coupon. The bond currently sells for $950. The company also pays $5 per bond in annual administrative fees to its bond trustee; these fees are tax-deductible. The company's tax rate is 25%. What is the approximate after-tax cost of this debt?

  1. 5.25%
  2. 5.39%
  3. 5.89% (correct answer)
  4. 6.26%
Explanation: The after-tax cost of debt should be based on the bond's yield to maturity (YTM). Administrative fees paid to a trustee are an operating expense, not a component of the financing cost (interest), and should be excluded from the YTM calculation. To find the YTM: N = 8; PV = -$950; PMT = $70; FV = $1,000. Solving for I/Y gives a pre-tax cost of debt of 7.85%. The after-tax cost is YTM × (1 - Tax Rate) = 7.85% × (1 - 0.25) = 5.89%.

Question 12

A putable bond issued by a company is trading at a yield to maturity of 5.5%. A comparable straight (non-putable) bond from the same issuer trades at a yield to maturity of 6.0%. For capital budgeting purposes, which rate is a better estimate of the company's pre-tax cost of debt?

  1. 5.5%, because it is the actual yield paid on the putable bond.
  2. 5.75%, representing the average of the two yields.
  3. Neither, as the firm should use the yield on its convertible debt instead.
  4. 6.0%, because the put option's value lowers the stated yield on the putable bond. (correct answer)
Explanation: When determining a company's cost of debt for capital budgeting, you need to identify the "true" borrowing cost without the influence of embedded options that artificially lower the stated yield. A putable bond contains an embedded put option that allows bondholders to sell the bond back to the issuer under certain conditions. This option has value to investors, so they're willing to accept a lower yield in exchange for this protection. The 5.5% yield on the putable bond reflects this trade-off – investors are essentially paying for the put option by accepting below-market returns. The straight bond's 6.0% yield represents the company's true borrowing cost without any embedded options. This is the rate that reflects the company's actual credit risk and market conditions. For capital budgeting decisions, you want this "clean" cost of debt because future projects won't necessarily have the same embedded options. Answer A is incorrect because the 5.5% yield understates the true cost of debt due to the valuable put option. Answer B wrongly assumes you should average the yields, but this ignores the economic reality that the put option creates value for bondholders. Answer C is incorrect because convertible debt would introduce yet another embedded option (the conversion feature) that would further distort the true borrowing cost. Study tip: When evaluating cost of debt, always strip away the effects of embedded options. Look for the yield on "plain vanilla" debt to get the most accurate estimate of the company's true borrowing cost for capital budgeting purposes.

Question 13

A company has issued floating-rate notes that pay a coupon equal to the 90-day SOFR plus a spread of 200 basis points. The coupon rate resets quarterly. At the time of a WACC calculation, the 90-day SOFR is 4.5%. Which of the following is the best estimate of the current pre-tax cost of this floating-rate debt?

  1. 2.00%, based on the fixed spread.
  2. 4.50%, based on the current benchmark rate.
  3. 6.50%, based on the current benchmark rate plus the spread. (correct answer)
  4. The yield to maturity of the company's long-term fixed-rate bonds.
Explanation: The cost of floating-rate debt is the current rate that would be paid. This is calculated by taking the current value of the benchmark reference rate and adding the quoted spread. In this case, the pre-tax cost of debt is the current SOFR (4.50%) plus the spread (200 basis points, or 2.00%), which equals 6.50%. Using the spread alone, the benchmark rate alone, or the yield on fixed-rate debt would be an incorrect estimation.

Question 14

A credit rating agency downgrades a company's debt from A to BBB. The risk-free rate is 4.0%. Credit spreads for A-rated debt are 1.2%, and spreads for BBB-rated debt are 2.0%. If the company's tax rate is 25%, what is the expected increase in its after-tax marginal cost of debt due to the downgrade?

  1. 0.60% (correct answer)
  2. 0.80%
  3. 1.30%
  4. 1.50%
Explanation: First, calculate the after-tax cost of debt before and after the downgrade. Before (A-rated): Pre-tax cost = 4.0% + 1.2% = 5.2%. After-tax cost = 5.2% × (1 - 0.25) = 3.90%. After (BBB-rated): Pre-tax cost = 4.0% + 2.0% = 6.0%. After-tax cost = 6.0% × (1 - 0.25) = 4.50%. The increase is the difference between the new and old after-tax costs: 4.50% - 3.90% = 0.60%.

Question 15

An analyst is calculating a company's cost of debt. The company has convertible bonds outstanding that have a yield to maturity of 4.5%. A comparable straight bond from the same issuer has a yield to maturity of 6.5%. Which rate is the most appropriate to use as the pre-tax cost of debt in a WACC calculation, and why?

  1. 4.5%, because it is the actual yield the company pays on this specific debt issue.
  2. 5.5%, as it is the average of the convertible and straight bond yields.
  3. Neither, because the cost of debt for convertible bonds cannot be directly determined.
  4. 6.5%, because it represents the cost of pure debt financing without the conversion feature. (correct answer)
Explanation: When calculating the cost of debt for WACC, you need to determine what the company would pay for pure debt financing, not debt with embedded equity features. Convertible bonds contain an option for bondholders to convert their bonds into stock, which makes them hybrid securities—part debt, part equity. The convertible bond's 4.5% yield is artificially low because investors accept lower interest payments in exchange for the valuable conversion option. This yield doesn't represent the true cost of debt financing since part of the investor's expected return comes from the potential equity upside. The comparable straight bond's 6.5% yield reflects what investors demand for pure debt exposure to this company's credit risk, without any equity sweeteners. Therefore, 6.5% is the appropriate pre-tax cost of debt because it represents the cost of pure debt financing without the conversion feature—this is answer D. Here's why the other options miss the mark: A) uses 4.5%, but this understates the true debt cost since it reflects compensation for both debt and the conversion option. B) suggests averaging to 5.5%, but there's no theoretical basis for this approach—it arbitrarily splits the difference without economic reasoning. C) claims the cost cannot be determined, but we can estimate it using comparable straight debt from the same issuer. Study tip: Remember that convertible securities always trade at lower yields than comparable straight debt due to their embedded options. For WACC calculations, always use the yield on comparable non-convertible debt to capture the true cost of debt financing.

Question 16

A company's 15-year, 10% annual coupon bond is trading at $1,150. The bond is callable in 5 years at a call price of $1,050. The company's tax rate is 25%. What is the appropriate after-tax cost of debt for the company to use in its WACC calculation?

  1. 5.95% (correct answer)
  2. 6.14%
  3. 7.50%
  4. 7.93%
Explanation: When a bond is callable, the cost of debt is the lower of its yield to maturity (YTM) or yield to call (YTC). YTM calculation: N=15, PV=-1150, PMT=100, FV=1000. This gives I/Y (YTM) = 8.19%. YTC calculation: N=5, PV=-1150, PMT=100, FV=1050 (call price). This gives I/Y (YTC) = 7.93%. Since YTC (7.93%) is lower than YTM (8.19%), the pre-tax cost of debt is 7.93%. The after-tax cost is 7.93% × (1 - 0.25) = 5.95%.

Question 17

A company issues a 10-year, 5% annual coupon bond with a $1,000 face value. The bond is issued at 98% of par. Flotation costs are 2% of the face value. If the company's marginal tax rate is 21%, what is the after-tax cost of this debt?

  1. 3.95%
  2. 4.16%
  3. 4.40% (correct answer)
  4. 5.56%
Explanation: First, calculate the net proceeds to the company. The issue price is 98% of $1,000, which is 980.Theflotationcostsare2980. The flotation costs are 2% of the face value (1,000), which is $20. Net proceeds (the initial cash inflow, or PV) = $980 - $20 = 960.Next,calculatethepre−taxcostofdebt(YTM)usingthesenetproceeds:N=10;PV=−960. Next, calculate the pre-tax cost of debt (YTM) using these net proceeds: N = 10; PV = -960; PMT = $50; FV = $1,000. Solving for I/Y gives a YTM of 5.56%. Finally, calculate the after-tax cost: 5.56% × (1 - 0.21) = 4.40%.

Question 18

A company needs to finance a new 15-year project. It can issue 10-year bonds with a yield of 6.0% or 20-year bonds with a yield of 6.5%. The company's tax rate is 25%. Based on the financing principle of maturity matching, what is the most appropriate after-tax cost of debt to use in the project's capital budget?

  1. 4.50%
  2. 4.69%
  3. 4.88% (correct answer)
  4. 6.25%
Explanation: The maturity matching principle suggests that the maturity of financing should match the life of the asset being financed. Since the project has a 15-year life, the 20-year bond is a better maturity match than the 10-year bond. Therefore, the cost of debt associated with the 20-year bond should be used. The pre-tax cost is 6.5%. The after-tax cost is 6.5% × (1 - 0.25) = 4.88%.

Question 19

A firm's marginal tax rate is expected to increase from 21% to 25% next year. Its pre-tax cost of debt is expected to remain stable at 7.0%. What will be the effect of this tax rate change on the firm's after-tax cost of debt?

  1. It will increase from 5.25% to 5.53%.
  2. It will remain unchanged because the pre-tax cost is stable.
  3. It will increase by 4 percentage points.
  4. It will decrease from 5.53% to 5.25%. (correct answer)
Explanation: When you encounter questions about tax effects on debt costs, remember that debt interest is tax-deductible, creating a "tax shield" that reduces the effective cost of borrowing. The after-tax cost of debt formula is: After-tax cost=Pre-tax cost×(1−Tax rate)\text{After-tax cost} = \text{Pre-tax cost} \times (1 - \text{Tax rate}) Let's calculate the after-tax cost for both years. Currently, with a 21% tax rate: 7.0%×(1−0.21)=7.0%×0.79=5.53%7.0\% \times (1 - 0.21) = 7.0\% \times 0.79 = 5.53\% Next year, with a 25% tax rate: 7.0%×(1−0.25)=7.0%×0.75=5.25%7.0\% \times (1 - 0.25) = 7.0\% \times 0.75 = 5.25\% The after-tax cost decreases from 5.53% to 5.25%, making D correct. Here's why the other answers miss the mark: A reverses the calculation, showing an increase when there should be a decrease. This reflects a fundamental misunderstanding of how tax shields work. B incorrectly assumes that stable pre-tax costs mean stable after-tax costs, ignoring the tax effect entirely. C confuses the 4 percentage point increase in the marginal tax rate (from 21% to 25%) with the effect on debt cost, but these are completely different metrics. The key insight is counterintuitive: higher tax rates actually reduce your after-tax borrowing costs because you get larger tax deductions. Remember this inverse relationship—when tax rates rise, after-tax debt costs fall, making debt financing relatively more attractive compared to equity.

Question 20

A company has an outstanding bond with 10 years to maturity, a par value of $1,000, and an 8% semi-annual coupon. The bond's current market price is $1,100. If the company's marginal tax rate is 25%, what is its after-tax cost of debt?

  1. 4.85%
  2. 4.91% (correct answer)
  3. 6.00%
  4. 6.54%
Explanation: The after-tax cost of debt is the yield to maturity (YTM) adjusted for taxes. First, calculate the YTM. Since the bond pays a semi-annual coupon, the inputs for a financial calculator are: N = 10 × 2 = 20; PV = -1,100;PMT=(1,100; PMT = (1,000 × 8%) / 2 = $40; FV = $1,000. Solving for the interest rate gives a semi-annual yield (I/Y) of 3.27%. The annualized YTM is 3.27% × 2 = 6.54%. This is the pre-tax cost of debt. The after-tax cost of debt is YTM × (1 - Tax Rate) = 6.54% × (1 - 0.25) = 4.91%.