18 min
Income Statement Architecture
Understand revenue, COGS, gross profit, operating expenses, EBITDA, EBIT, taxes, and net income.
Core concepts
- - Is the metric defined consistently across historical and forecast periods?
- - Does the formula use the correct sign convention?
- - Can the assumption be defended with operating evidence?
Example
The income statement explains performance over a period, but it is built on accrual accounting rather than pure cash movement. A good analyst separates operating performance from financing, non-operating items, and tax effects before using the statement for valuation. EBITDA is useful because it normalizes D&A and financing choices, but it must never be treated as free cash flow.
Formula block
EBITDA = Revenue - COGS - Cash Operating ExpensesPractice assignment
Calculate gross margin, EBITDA margin, and EBIT margin for a company with $250M revenue, $145M COGS, $62M opex, and $11M D&A.
Expected deliverable
Annotate the schedule with source, assumption owner, formula, and reasonableness check so another reviewer can audit it without your narration.
Mistakes to avoid
- - Hardcoding a calculated output instead of linking it to the operating driver.
- - Mixing enterprise value and equity value when moving between multiples and per-share metrics.
- - Using a positive working-capital sign convention in one schedule and a negative convention somewhere else.
- - Applying a forward multiple to a historical denominator or a historical multiple to a forward denominator.