Financial modelling terms explained


Unlock the secrets of financial modeling with our comprehensive guide to WACC.

Understanding the Weighted Average Cost of Capital (WACC) is crucial for anyone involved in financial modelling. This term is a key component in corporate finance and investment banking. It is a measure that provides insights into the average rate that a company is expected to pay to finance its assets. The WACC is the minimum return that a company must earn on its existing asset base to satisfy its creditors, owners, and other providers of capital.

Understanding the Concept of WACC

The WACC is a firm's average cost of capital, where each category of capital is proportionately weighted. It takes into account the relative weights of equity and debt in the capital structure of a company. The cost of each type of capital is weighted by its proportion of the total capital and they are added together. This process is a key input in discounted cash flow (DCF) analysis and is frequently the hurdle rate for company investments.

The WACC formula is expressed as the multiplication of the cost of each capital component by its proportional weight and then summing:

WACC = (E/V x Re) + ((D/V x Rd) x (1 – Tc))


  • E = Market value of equity
  • V = Market value of equity + market value of debt
  • Re = Cost of equity
  • D = Market value of debt
  • Rd = Cost of debt
  • Tc = Corporate tax rate

Importance of WACC in Financial Modelling

WACC plays a vital role in financial modelling as it is often used as a discount rate for future cash flows in order to derive a business's net present value. WACC is also a critical factor in investment decisions. When the return on a project is above the WACC, the project is likely to generate value for the company.

Moreover, WACC is used by financial analysts to determine if investment opportunities are worthwhile to pursue. If the expected return from an investment is less than the WACC, the investment should not be undertaken. The company would be better off investing this capital back into its business or distributing it to shareholders.

Calculating WACC

Cost of Equity

The cost of equity is the return required by an equity investor to hold a particular investment. It is often estimated using the Capital Asset Pricing Model (CAPM), which calculates the cost of equity as follows:

Re = Rf + β(Rm - Rf)


  • Rf = Risk-free rate
  • β = Beta of the investment
  • Rm = Expected market return

Cost of Debt

The cost of debt is the effective interest rate a company pays on its debts. It’s typically calculated as the yield to maturity on the company's bonds. However, companies can also use the interest rate on a risk-free bond plus a risk premium. The cost of debt is also adjusted for taxes because interest expense is tax-deductible.

Weight of Equity and Debt

The weights of equity and debt are calculated as a proportion of total capital. The market values of equity and debt are used to give a more accurate picture of a company's capital structure. These weights are used in the WACC formula to ensure that the cost of each type of capital is proportionately reflected.

Limitations of WACC

While WACC is a crucial element in financial modelling, it does have its limitations. It assumes that the company's financial structure, business risk, and tax rate will remain constant. This is rarely the case in the real world. Furthermore, WACC is a firm-wide estimate of the cost of capital, and it may not accurately reflect the cost of capital for individual projects.

Moreover, the calculation of WACC involves the estimation of the cost of equity and the cost of debt, which can be subjective. The CAPM model used to estimate the cost of equity has been criticized for its assumptions about market behavior and risk. Similarly, the cost of debt can be difficult to estimate for companies without publicly traded bonds.


Despite its limitations, WACC is a vital concept in financial modelling and corporate finance. It provides a benchmark for the minimum return required on an investment. Understanding how it is calculated and its implications can help in making informed investment and financial decisions.

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