What does cost of capital mean?
Cost of capital is the return required by the providers of debt and equity capital for the risk they bear.
A practical example
Begin with a clearly defined reporting period and list the amounts or events included in the measure. Reconcile the result to the relevant cash-flow, income-statement or balance-sheet line before comparing it with another period or business.
How to analyze it
- Name the measure.
State the exact definition and period. - Trace the inputs.
Identify the source statement, schedule or transaction for each figure. - Reconcile the result.
Check that subtotals connect to the appropriate statement or cash balance. - Compare consistently.
Use the same definition for every period or company in the comparison.
When should you use cost of capital?
Use a weighted framework only after defining each capital source, weight and required return.
Limitations and common mistakes
Book weights, market weights and target weights can produce different results.
Do not mix annual figures with monthly figures, ending balances with averages, or percentages with whole numbers. Record the definition used so another person can reproduce the result.
Frequently asked questions
What is cost of capital?
Cost of capital is the return required by the providers of debt and equity capital for the risk they bear.
How should I use cost of capital?
Use the formula only after matching every input to the same period, unit and definition. Then compare the result with a worked example and the decision you are trying to make.
What is the most common mistake with cost of capital?
Book weights, market weights and target weights can produce different results.
Can I calculate cost of capital in a spreadsheet?
Yes. Reproduce the displayed equation with separate cells for each input, keep percentages as decimals, and test the spreadsheet against the worked example before replacing the sample figures.
Sources and methodology
This page uses the Financial definitions for the underlying financial or reporting context. Spreadsheet-related behavior is checked against Microsoft’s financial-function documentation. Examples are illustrative and use the formula displayed on the page.