After completing this lesson, you’ll be able to calculate and interpret the most commonly used financial ratios, perform horizontal and vertical analysis, and explain what these tools reveal (and don’t reveal) about a business.
Why raw numbers aren’t enough
A business with 500,000 top line means something very different for a solo consultant than for a manufacturing plant with 50 employees and $480,000 in costs.
Financial statement analysis converts raw numbers into relationships and trends that allow comparison — across time periods, across competitors, and across industries. The three main tools are horizontal analysis, vertical analysis, and ratio analysis.
Horizontal analysis (trend analysis)
Horizontal analysis compares the same line item across two or more periods. You calculate the dollar change and the percentage change for every major line item, then look for patterns.
Worked example. Here’s a simplified income statement for two years:
| Year 1 | Year 2 | $ Change | % Change | |
|---|---|---|---|---|
| Revenue | $400,000 | $500,000 | $100,000 | 25.0% |
| Cost of Goods Sold | $240,000 | $320,000 | $80,000 | 33.3% |
| Gross Profit | $160,000 | $180,000 | $20,000 | 12.5% |
| Operating Expenses | $100,000 | $115,000 | $15,000 | 15.0% |
| Net Income | $60,000 | $65,000 | $5,000 | 8.3% |
Revenue grew 25%, which looks good. But cost of goods sold grew 33.3% — faster than revenue. That squeezed the gross profit margin. Operating expenses rose 15%, which is slower than revenue growth — that’s a positive sign. Net income grew only 8.3%, much less than revenue, because the cost increases ate into the gain. Without horizontal analysis, “$65,000 in net income” doesn’t tell you any of this.
Formulas:
- Dollar change = Current period amount − Prior period amount
- Percentage change = Dollar change / Prior period amount × 100
Vertical analysis (common-size statements)
Vertical analysis expresses every line item as a percentage of a base figure. For income statements, the base is revenue. For balance sheets, the base is total assets. This produces “common-size” statements that make companies of different sizes comparable.
Worked example. Here’s a common-size income statement:
| Amount | % of Revenue | |
|---|---|---|
| Revenue | $500,000 | 100.0% |
| Cost of Goods Sold | $320,000 | 64.0% |
| Gross Profit | $180,000 | 36.0% |
| Salaries | $60,000 | 12.0% |
| Rent | $24,000 | 4.8% |
| Marketing | $16,000 | 3.2% |
| Other Operating Expenses | $15,000 | 3.0% |
| Total Operating Expenses | $115,000 | 23.0% |
| Net Income | $65,000 | 13.0% |
Now you can compare this business to a competitor that has $2 million in revenue. If the competitor’s COGS is 70% of revenue and this business’s is 64%, this business is more efficient at production or purchasing — regardless of their size difference.
Liquidity ratios
Liquidity ratios answer a simple question: can the business pay its short-term obligations?
Current ratio = Current Assets / Current Liabilities
This measures whether the business has enough short-term assets to cover short-term debts. Example: a company with 100,000 in current liabilities has a current ratio of 1.5. That means 1.00 of current liabilities.
Quick ratio = (Current Assets − Inventory) / Current Liabilities
The quick ratio is more conservative. It strips out inventory because inventory might not convert to cash quickly — especially if it’s seasonal, perishable, or specialized. Using the same company with 150,000 − 100,000 = 1.1.
Interpretation. A current ratio below 1.0 means current liabilities exceed current assets, which is a warning sign. But “good” ratios vary by industry [citation needed]. A grocery store with fast inventory turnover can operate comfortably with a lower current ratio than a furniture manufacturer with slow-moving stock.
Profitability ratios
Profitability ratios measure whether the business generates adequate returns relative to its revenue, assets, or equity.
Worked example. Consider a company with these numbers:
| Amount | |
|---|---|
| Revenue | $500,000 |
| Cost of Goods Sold | $320,000 |
| Net Income | $65,000 |
| Total Assets | $400,000 |
| Total Equity | $250,000 |
Gross profit margin = (Revenue − COGS) / Revenue = (320,000) / $500,000 = 36.0%. This measures production and purchasing efficiency — how much of each revenue dollar survives after direct costs.
Net profit margin = Net Income / Revenue = 500,000 = 13.0%. This is the bottom line — what percentage of each revenue dollar becomes profit after all expenses.
Return on assets (ROA) = Net Income / Total Assets = 400,000 = 16.3%. This measures how effectively the business uses its assets to generate profit.
Return on equity (ROE) = Net Income / Total Equity = 250,000 = 26.0%. This measures the return generated for the owners on their investment.
Notice that ROE (26.0%) is higher than ROA (16.3%). That gap exists because the company uses debt financing in addition to equity. When a business earns more on borrowed money than it pays in interest, the extra return flows to the owners — this is the effect of leverage.
Leverage ratios
Leverage ratios reveal how the business is financed — the mix of debt and equity.
Debt-to-equity ratio = Total Liabilities / Total Equity. Using the same company: total liabilities are 400,000 total assets − 150,000 / 0.60 of debt for every $1.00 of equity.
Debt ratio = Total Liabilities / Total Assets = 400,000 = 37.5%. Just over a third of the company’s assets are financed by debt.
Debt isn’t inherently bad. Borrowing can amplify returns for owners (leverage) because the business can invest more than the owners put in. But leverage also amplifies risk — if the business hits a downturn, those debt payments don’t shrink. A highly leveraged company can go from profitable to insolvent faster than a conservatively financed one.
Limitations
Financial statement analysis is powerful, but it has blind spots:
- Historical cost. Financial statements report what assets cost when they were acquired, not what they’re worth today. A building bought for 1 million, but the balance sheet doesn’t reflect that.
- Accounting standards. Different companies might make different (but equally valid) choices about depreciation methods, revenue recognition timing, or inventory costing. These choices affect the numbers ratios are built on.
- Non-financial factors. Ratios don’t capture management quality, employee morale, pending lawsuits, competitive dynamics, or technological shifts.
- Industry differences. A 2:1 current ratio is strong for a retailer but irrelevant for a software company with no inventory. A 50% debt ratio is normal in real estate but alarming in consulting [citation needed]. Always compare within the same industry and over multiple periods.
Ratios are a starting point for questions, not a source of final answers.
Self-check exercises
Exercise 1. A company has these balance sheet items: Cash 55,000, Inventory 10,000, Accounts Payable 30,000. Calculate the current ratio and quick ratio. Interpret the results.
Answer
Current Assets = 55,000 + 10,000 = $140,000
Current Liabilities = 30,000 = $90,000
Current ratio = 90,000 = 1.56. The business has 1.00 of current liabilities — it can cover its short-term obligations.
Quick ratio = (35,000) / 105,000 / $90,000 = 1.17. Even after excluding inventory, the business has enough liquid assets to cover current liabilities, though with less margin.
The gap between the two ratios ($0.39) tells you that inventory makes up a meaningful portion of current assets. If that inventory is hard to sell quickly, the quick ratio gives a more realistic picture of short-term liquidity.
Exercise 2. A business has Revenue of 520,000, and Net Income of $84,000. Calculate the gross profit margin and net profit margin. What does the gap between them tell you?
Answer
Gross profit margin = (520,000) / 280,000 / $800,000 = 35.0%
Net profit margin = 800,000 = 10.5%
The gap between them (35.0% − 10.5% = 24.5 percentage points) represents operating expenses as a share of revenue. The business keeps 35 cents of every revenue dollar after direct costs, but operating expenses consume another 24.5 cents, leaving 10.5 cents as profit. If the business wants to improve net margin, it needs to examine those operating expenses — the production side is already delivering a solid gross margin.
Exercise 3. Company A has ROE of 25% and a debt-to-equity ratio of 3:1. Company B has ROE of 15% and a debt-to-equity ratio of 0.5:1. Which company is “better”?
Answer
Neither is objectively better — it depends on how you weigh return against risk.
Company A’s higher ROE is partially driven by heavy leverage. A 3:1 debt-to-equity ratio means the company has 1 of equity. Borrowed money is amplifying the owners’ returns, but it also amplifies risk. If revenue drops, Company A still owes interest and principal payments on all that debt.
Company B’s ROE is lower, but it comes with much less financial risk. A 0.5:1 debt-to-equity ratio means the company relies primarily on equity financing. It’s more resilient to downturns.
An investor who prioritizes stability might prefer B. An investor who prioritizes returns and tolerates risk might prefer A. The key insight is that you can’t evaluate ROE without also looking at how much leverage produced it.
Exercise 4. Perform vertical analysis on the following income statement by expressing each line as a percentage of revenue.
| Amount | |
|---|---|
| Revenue | $250,000 |
| Cost of Goods Sold | $150,000 |
| Gross Profit | $100,000 |
| Salaries | $40,000 |
| Rent | $12,000 |
| Utilities | $3,000 |
| Marketing | $10,000 |
| Net Income | $35,000 |
Answer
| Amount | % of Revenue | |
|---|---|---|
| Revenue | $250,000 | 100.0% |
| Cost of Goods Sold | $150,000 | 60.0% |
| Gross Profit | $100,000 | 40.0% |
| Salaries | $40,000 | 16.0% |
| Rent | $12,000 | 4.8% |
| Utilities | $3,000 | 1.2% |
| Marketing | $10,000 | 4.0% |
| Net Income | $35,000 | 14.0% |
The business retains 40 cents of every revenue dollar after COGS. Salaries are the largest operating expense at 16% of revenue. The net profit margin of 14% means the business keeps 14 cents of every dollar earned.
What comes next
You now have the tools to read and analyze financial statements. The next lesson covers bank reconciliation — the process of matching a company’s cash records against the bank’s records to catch errors and unauthorized transactions.