What is WACC? The key to evaluating investment profitability

When we need to decide to invest in a particular project, many investors often look only at the expected rate of return. However, that is only half of the investment picture, because we also need to consider the cost of capital used to fund the project. This is where WACC (Weighted Average Cost of Capital) plays an important role. It tells us how much it costs to raise funds, and this article will help you understand WACC deeply—from its meaning, components, calculation formulas, to effective application.

What is WACC and Why Is It Important

WACC stands for Weighted Average Cost of Capital. It means the average cost of funds. This is the amount a business must pay to raise capital for operations. In other words, it shows how much the company needs to pay to obtain its capital.

Investors use the WACC as a criterion for decision-making. If the expected return rate exceeds WACC, it indicates the project is worth investing in. But if it’s lower, the investment should be reduced.

Main Components of WACC

The WACC consists of two main financial costs:

###Cost of Debt(

This is the expense when the company borrows money from banks or financial institutions, expressed as an interest rate the company must pay. The advantage of borrowing is that interest is tax-deductible, which reduces the actual cost.

)Cost of Equity###

This is the rate of return that shareholders and investors expect for their investment. This component is riskier because shareholders are owners of the residual after all debts are paid.

WACC Calculation Formula You Should Know

The WACC formula is as follows:

WACC = (D/V × Rd × )(1-Tc)( + (E/V × Re)

where:

• D/V = proportion of debt relative to total capital
• Rd = cost of debt )interest rate(
• Tc = corporate income tax rate
• E/V = proportion of equity relative to total capital
• Re = cost of equity )expected return rate(

Real-World WACC Estimation Example

Let’s look at an example of company ABC with the following capital structure:

Debt of 100 million baht )60%( and equity of 160 million baht )40%(

• Loan interest rate: 7% per year
• Corporate tax rate: 20%
• Expected return rate: 15%

Calculation steps:

WACC = )100/260 × 0.07 × 0.8( + )160/260 × 0.15( WACC = )0.3846 × 0.07 × 0.8( + )0.6154 × 0.15( WACC = 0.0215 + 0.0923 WACC ≈ 11.38%

Comparing this with the expected return of 15%, which is higher than WACC 11.38%, indicates that this project is worth investing in.

Is a Lower WACC Always Better?

Generally, a lower WACC indicates the company has a lower cost of raising funds, which is a good sign. However, it’s not always straightforward.

An appropriate WACC depends on many factors, such as industry, risk level, investment policy, and economic conditions. Therefore, WACC should be considered alongside other financial metrics like NPV )Net Present Value( and IRR )Internal Rate of Return(.

The Optimal Capital Structure

The target capital structure is to balance debt and equity to achieve two goals:

1. Minimize WACC to reduce the cost of capital
2. Increase the company’s market value by making shareholders wealthier

Companies can choose various ways to raise funds:

• Use only equity: WACC will be high because shareholders bear all the risk
• Use debt: lowers WACC but increases financial risk
• Combine appropriately: achieve a balance between cost and risk

Cautions When Using WACC

) 1. WACC Does Not Predict Future Changes

WACC is calculated based on current data and does not account for future changes in interest rates, debt levels, or risk.

( 2. WACC Does Not Reflect Project-Specific Risks

Different investments have different risks, but WACC uses a single figure, which may lead to inaccurate assessments of high-risk projects.

) 3. Calculation Complexity

Requires current, accurate data, including estimates of the cost of equity, which may not be straightforward.

4. WACC Is an Approximate Value

There is no perfect calculation of WACC because economic and financial factors constantly change.

How to Maximize the Benefits of WACC

1. Use with Other Metrics

Just as a doctor doesn’t rely on a single test, don’t rely solely on WACC. Use it together with NPV, IRR, and other indicators to fully understand the investment’s value.

2. Regularly Update WACC

Just as your home’s value changes over time, update your WACC calculations periodically to reflect changes in interest rates, debt levels, and economic conditions. This helps you monitor whether the investment remains worthwhile.

Summary

Now you probably understand what WACC is, what it consists of, how to calculate it, and how to apply it effectively. WACC is a valuable financial tool for evaluating investment profitability, business valuation, and capital structure decisions.

Although WACC is very useful, it must be used carefully, acknowledging its limitations and considering other influencing factors. By thoughtfully combining WACC with other analyses, you can make smarter, more efficient investment decisions.