Common-Size Financial Statements and Trend Analysis
By SimplyCPA · 11 October 2026
On this page (5)
- Vertical (common-size) analysis: Every line as a percentage of a base in the same period — sales for the income statement, total assets for the balance sheet.
- Horizontal (trend) analysis: Each line compared over time, either as a change from the prior year or as an index against a base year.
- Why it helps: It removes size, so you can compare a small company with a large one, or this year with five years ago.
- Watch for: Costs growing faster than revenue, receivables growing faster than sales, and shifts in the mix of assets or funding.
- Limits: Percentages hide absolute size, base-year choice affects trends, and different accounting policies distort comparisons.
Vertical analysis: common-size statements
A common-size income statement expresses every line as a percentage of net sales. A common-size balance sheet uses total assets (or total liabilities and equity).
| Income statement | Company A | % of sales | Company B | % of sales |
|---|---|---|---|---|
| Net sales | $500,000 | 100% | $8,000,000 | 100% |
| Cost of goods sold | 300,000 | 60% | 5,200,000 | 65% |
| Gross profit | 200,000 | 40% | 2,800,000 | 35% |
| Operating expenses | 150,000 | 30% | 1,840,000 | 23% |
| Operating income | 50,000 | 10% | 960,000 | 12% |
Company B is 16 times larger, but the percentages show the real story: A earns a better gross margin, while B runs its overheads far more efficiently and ends up with the higher operating margin.
Horizontal analysis: change and trend
Year-on-year change = (Current year − Prior year) ÷ Prior year.
Trend index = Current year amount ÷ Base year amount × 100.
| Year 1 (base) | Year 2 | Year 3 | |
|---|---|---|---|
| Sales | $1,000,000 (100) | $1,100,000 (110) | $1,210,000 (121) |
| Accounts receivable | $100,000 (100) | $125,000 (125) | $160,000 (160) |
| Operating expenses | $300,000 (100) | $345,000 (115) | $400,000 (133) |
Sales grew 21% over two years, but receivables grew 60% and operating expenses 33%. That's a warning sign: slower collections (or aggressive revenue recognition) and costs outpacing growth.
What to look for
- Margin squeeze — cost of sales rising as a percentage of revenue.
- Working capital drift — receivables or inventory growing faster than sales.
- Funding shifts — debt rising as a share of total liabilities and equity.
- Asset mix — a growing share of intangibles or goodwill after acquisitions.
Limitations
- A percentage says nothing about absolute size — 5% of a tiny base can be immaterial.
- Trend percentages are sensitive to the base year; a bad base year flatters everything after it.
- Comparisons across companies are distorted by different accounting policies (inventory methods, capitalisation choices) and by inflation.
- Negative or zero base amounts make percentage changes meaningless.
Exam tip: BAR task-based simulations often give two or three years of statements and ask you to compute common-size figures and pick the explanation that fits. Do the arithmetic quickly and spend your time on interpretation.
See also financial statement analysis ratios.