Skip to content

Financial Management · Capital structure theories and practical considerations

Traditional View of Capital Structure Explained for ACCA FM

Updated 11 October 2026 · Fact-checked

The traditional view says a company can lower its WACC by adding some cheap debt. Beyond a certain gearing level, financial risk pushes up the cost of both equity and debt, so WACC rises. The lowest point of the U-shaped WACC curve is the optimal capital structure, where company value is highest.

Understand Traditional View of Capital Structure

Start with a company funded only by equity. Shareholders carry all the business risk, so they demand a high return. The WACC equals the cost of equity.

Now add some debt. Debt is cheaper than equity for two reasons. Lenders are paid first and often have security, so they accept a lower return. Interest is also usually tax-deductible, which cuts the cost further. At low gearing, the extra financial risk is small, so the cost of equity rises only slightly. The cheap debt makes up a bigger share of the mix, so WACC falls.

Keep adding debt and the picture changes. Interest must be paid whatever profits are. Shareholders see their earnings become more volatile and the risk of failure grows. They demand a sharply higher return. Lenders also see more risk, so the cost of debt itself starts to rise. At some point the rising costs outweigh the benefit of having more cheap debt. WACC rises.

So the WACC curve is U-shaped. The bottom of the U is the optimal capital structure. At this point WACC is lowest and the market value of the company (the present value of its cash flows discounted at WACC) is highest. Management should aim to move gearing towards this level.

This is the main contrast with Modigliani and Miller (no taxes), who say WACC and value do not change with gearing. The traditional view is a theory based on observation and judgement. It gives no formula for finding the optimal point. You can only show it using numbers given in the question.

Key rules to remember

Weighted average cost of capital
WACC = [Ke × E ÷ (E + D)] + [Kd × (1 − T) × D ÷ (E + D)]
E and D are market values of equity and debt. Kd(1 − T) is the after-tax cost of debt. Use the version that matches the data given.
Value of the company at a given WACC
Value = Annual cash flows to all providers of finance ÷ WACC
Applies when cash flows are constant in perpetuity. A lower WACC gives a higher value.
Optimal capital structure rule
Optimal gearing = the gearing level with the lowest WACC (and so highest value)
Under the traditional view this is an interior point, not zero debt and not maximum debt.

How to solve Traditional View of Capital Structure questions

Use this method for any question that asks you to explain the traditional view, compare it with other theories or find the best gearing from data.

  1. 1Identify what is asked: explanation, comparison with Modigliani and Miller, or a calculation of WACC at different gearing levels.
  2. 2State the starting point: all-equity, WACC equals Ke. Debt is cheaper than equity because of lower risk to lenders and tax relief on interest.
  3. 3For each gearing level given, find the market values of equity and debt and the weights E ÷ (E + D) and D ÷ (E + D).
  4. 4Calculate WACC at each level using the Ke and Kd supplied. Use after-tax Kd if tax is stated.
  5. 5Compare the WACCs. The lowest is the optimal level. Note where WACC starts to rise and say why: higher financial risk raises Ke and later Kd.
  6. 6If asked for value, divide the relevant cash flow by WACC and show that value is highest where WACC is lowest.
  7. 7Add a short comment on limits: the theory is not exact and the real optimum depends on practical factors such as business risk and security available.

Quickest way: Table method for the optimal gearing level

When to use it: Use it when a Section B or C question gives Ke and Kd at several gearing levels and asks you to pick the best one.

  1. Draw a small table with columns: gearing, weight of equity, weight of debt, Ke, Kd after tax, WACC.
  2. Convert each gearing ratio into weights (for example, debt:equity of 1:4 gives 20% debt and 80% equity).
  3. Compute WACC row by row. Do not recompute the weights twice.
  4. Circle the lowest WACC. Check the trend: it should fall, then rise.
  5. Write one sentence: the optimal gearing is at the lowest WACC because value is highest there.

Common mistakes in Traditional View of Capital Structure

  • Saying the traditional view claims more debt always lowers WACC.

    Students remember the cheap debt point and forget the rising financial risk.

    Fix: Always describe both phases: WACC falls at low gearing, then rises at high gearing, giving a U-shape.

  • Confusing the traditional view with Modigliani and Miller.

    Both theories discuss gearing and WACC and the names are learned together.

    Fix: Traditional: an optimal gearing exists. M&M without tax: WACC is constant, so gearing is irrelevant. Write this contrast in one line.

  • Using the pre-tax cost of debt in WACC when tax rate is given.

    Rushing and forgetting the (1 − T) adjustment.

    Fix: Check for a tax rate in the question. If given, use Kd × (1 − T) unless the figure is already stated after tax.

  • Using book values for weights instead of market values.

    Balance sheet figures are easy to find.

    Fix: Use market values of equity and debt whenever they are given. Only use book values if nothing else is provided and say so.

  • Stating that the theory gives an exact optimal gearing ratio.

    Numerical questions give a clear answer, so students assume the theory always does.

    Fix: Say the optimum is found only from the data provided. In practice it cannot be calculated precisely.

  • Explaining the rise in WACC only by the cost of equity.

    Students link financial risk only to shareholders.

    Fix: Mention that at high gearing the cost of debt also rises as lenders face higher default risk.

Worked examples

Example 1

A company has the following capital structures. Tax rate is 25%. Gearing A: debt 10%, equity 90%, Ke 12%, pre-tax Kd 5%. Gearing B: debt 30%, equity 70%, Ke 13%, pre-tax Kd 6%. Gearing C: debt 50%, equity 50%, Ke 16%, pre-tax Kd 9%. Which gearing is optimal under the traditional view?

Show the solution
  1. After-tax Kd for A = 5% × 0.75 = 3.75%. For B = 6% × 0.75 = 4.5%. For C = 9% × 0.75 = 6.75%.
  2. WACC A = (0.90 × 12%) + (0.10 × 3.75%) = 10.8% + 0.375% = 11.175%.
  3. WACC B = (0.70 × 13%) + (0.30 × 4.5%) = 9.1% + 1.35% = 10.45%.
  4. WACC C = (0.50 × 16%) + (0.50 × 6.75%) = 8% + 3.375% = 11.375%.
  5. WACC falls from A to B, then rises at C. The lowest is B.

Answer: Gearing B (30% debt, 70% equity) is optimal, with a WACC of 10.45%. Beyond this point, higher risk raises Ke and Kd enough to push WACC up.

Example 2

A company generates constant annual cash flows of ₹60,00,000 before payments to finance providers, in perpetuity. At its current gearing the WACC is 12%. After moving to the optimal gearing, the WACC is 10%. Calculate the change in company value and explain it using the traditional view.

Show the solution
  1. Value at 12% = ₹60,00,000 ÷ 0.12 = ₹5,00,00,000.
  2. Value at 10% = ₹60,00,000 ÷ 0.10 = ₹6,00,00,000.
  3. Increase in value = ₹6,00,00,000 − ₹5,00,00,000 = ₹1,00,00,000.
  4. Explanation: moving to the optimal gearing adds cheap debt without yet raising Ke and Kd too much. WACC falls and the same cash flows are discounted at a lower rate, so value rises.

Answer: Company value rises by ₹1,00,00,000, from ₹5,00,00,000 to ₹6,00,00,000, because WACC falls from 12% to 10%.

Exam tips

  • In written parts, draw or describe the U-shaped WACC curve and say what happens to Ke, Kd and WACC in each phase.
  • Always link the lowest WACC to the highest company value. Markers look for this link.
  • Add a one-line comparison with Modigliani and Miller. It earns easy marks in Section C.
  • In objective tests, watch for the words 'optimal' and 'U-shaped'. These point to the traditional view, not M&M.
  • In calculations, show the weights, the after-tax Kd and each WACC. Method marks are given even if one number is wrong.

Practice questions from Capital structure theories and practical considerations

Traditional View of Capital Structure in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Traditional View of Capital Structure: frequently asked questions

What is the traditional theory of capital structure in ACCA FM?

It says WACC first falls as cheap debt is added, then rises as financial risk increases. The lowest point of the curve is the optimal gearing, where company value is highest.

What is the difference between the traditional view and Modigliani and Miller?

The traditional view says an optimal gearing level exists and that WACC changes with gearing. M&M without taxes says WACC and value are unaffected by gearing. M&M with tax says value rises with debt because of tax relief on interest.

Why does WACC rise at high gearing?

Shareholders face higher financial risk because interest must be paid regardless of profit, so they demand a higher return. Lenders also see a greater risk of default, so the cost of debt rises. These increases outweigh the gain from cheap debt.

Can I calculate the optimal gearing exactly?

No. The theory gives no formula. In exam questions you find the optimum by calculating WACC at the gearing levels given and choosing the lowest.