What Is Common-Size Analysis?

Common size analysis: a clearer way to evaluate financials

Imagine comparing your Q1 and Q2 financials side by side. Revenue is up 12% but expenses increased 15%. Is performance declining? Raw numbers alone tell an incomplete story.Common size analysis solves this by converting financial figures to percentages of a base value to create a standardised view. This reveals meaningful patterns regardless of company size. For example, each income statement line becomes a percentage of revenue, making it easier to catch anomalies.

Key takeaways:

Common size analysis standardises financial data by expressing items as percentages of a meaningful base figure.
Common size analysis enables more accurate comparisons across periods, divisions and competitors of different sizes.
The technique applies across income statements, balance sheets and cash flow statements.
The technique forms the foundation for both vertical analysis (proportions within a period) and horizontal analysis (trends over time).
Workday finance solutions automate comparisons and turn raw data into rich financial insights for faster decision-making.

In a financial review of Procter & Gamble, common size analysis revealed stable operating costs despite fluctuating profits. By showing expenses as a percentage of revenue, it spotlighted efficient cost control and steady profit margins for most years between the 2013–2023 analysis period. (ResearchGate, 2024)

What is common size analysis?

Common size analysis converts financial statement items into percentages. It expresses each line as a portion of a meaningful base figure, usually total assets or total revenue. Its goal is to highlight an organisation’s financial structure and performance trends regardless of company size.

Common size statements are also known as standardised or uniform statements. They offer two helpful views: vertical and horizontal analysis.

Common size statement vertical analysis vs. horizontal analysis

Vertical analysis examines proportions within a single financial period, while horizontal analysis – also known as common size trend analysis – tracks percentage changes over time. Each method reveals different insights about a company’s financial position and performance.

Vertical Analysis

Expresses each line item as a percentage of a base figure within the same period, such as one month.
Shows financial structure and relative importance of financial factors.
Helps identify unusual proportions compared to industry benchmarks.
Best for understanding current finances.

Horizontal Analysis

Tracks percentage changes of specific line items across multiple periods, such as year-over-year.
Reveals trends, growth patterns and potential problems over time.
Uses a base year as a reference point (often set at 100%).
Best for spotting directional shifts and long-term performance.

Why common size analysis became an essential tool in financial planning & analysis

Before common size analysis became mainstream, financial analysts faced a problem: How do you compare companies of different sizes or see how margins vary between periods? Raw numbers don’t tell the whole story. For example, a $2 million expense might be alarming for a small business but not so much for a global corporation.

To help investors understand proportions and relationships within the numbers, financial pros started converting line items to percentages instead. A financial analyst could then compare a corner store’s finances with a manufacturing giant’s using an even baseline.

Fast-forward to today, where common size financial analysis has moved from spreadsheets to more complex, automated systems for real-time insights and simple calculations. Modern AI-powered financial tools automatically convert raw data into percentage-based views to spot patterns you might otherwise miss, such as gradual shifts in expense ratios.

As a result, finance teams can spend more time using predictive analytics insights to make smart business decisions.

Did you know?

Common size analysis can be somewhat of a financial truth serum for CFOs. It often exposes inefficiencies, such as when a company’s most profitable product turns out to be less impressive once it considers percentages of sales instead of just dollar amounts.

Why common size analysis is essential for financial insight

When reviewing expenses, a $5,000 increase in office supplies might seem unimportant to a mid-sized company. But seeing it as a percentage jump from 1.2% to 1.8% of revenue signals a growing problem. Or, you might discover your R&D spending sits at 4% while industry leaders invest 7%, which could explain stalled innovation.

A percentage view levels the playing field. Small businesses can directly compare their margins with larger competitors, and division heads can benchmark performance across departments of different sizes. Finance teams can also spot concerning trends in expense ratios before they balloon into bigger budgeting problems.

Most importantly, these standardised views make financial data accessible to business leaders outside of finance. Executives can grasp key insights without getting lost in spreadsheets, essentially granting faster, more confident decision-making across the organisation.

How to do common size analysis

If you can calculate percentages, you can complete a common size analysis to identify proportional relationships that make financial comparisons simpler. Here’s how to do it.

1. Start with a clean statement

Use an accurate financial statement, such as a balance sheet, income statement or cash flow statement. Categorise the figures consistently across periods, and remove any one-time or outlier items that might skew your analysis if you want to focus on core operations.

For income statements, arrange items from revenue down to net income. For balance sheets, organise assets, liabilities and equity in their standard sections.

2. Identify your base

Select the reference figure against which you’ll measure everything else:

For income statements: Total revenue is typically the base
For balance sheets: Total assets is the standard base
For cash flow statements: Total cash flow or beginning cash balance often serves as the base

Some specialised analyses might use different bases, such as the cost of goods sold to analyse production expenses. To maintain accurate comparisons, keep the base you choose consistent throughout your analysis.

3. Apply the formula to each line item

Use the following formula to turn each line item into a comparable percentage:

Percentage = (Line item value ÷ base value) × 100

For example, if your company’s revenue is $1,000,000 and the cost of goods sold is $500,000, your calculation would look like this:

($500,000 ÷ $1,000,000) x 100 = 50%

This particular line tells you that 50 cents per revenue dollar goes towards the costs of goods.

4. Format the output

Present your common size analysis in a clear, readable format:

Create a table with both absolute values and percentages side by side
Use consistent decimal places (usually one or two is sufficient)
Include multiple periods for horizontal analysis
Add visual elements, such as conditional formatting, to highlight significant changes

Excel works well for common size analysis but requires manual setup. Next to your raw data, create a column for percentages, insert your formula and copy it down for each line. You’ll have to rebuild the spreadsheet whenever you start a new analysis.

You can also consider dedicated FP&A or reporting software. Workday Adaptive Planning and Workday Financial Management have AI-powered financial analysis tools that automate this entire process, generating common size comparisons instantly while adding context via industry benchmarks. The platform flags unusual variances and provides drill-down capabilities to investigate root causes for better decision-making.

Common size statement examples and use cases

The following real-world examples demonstrate how common size analysis reveals insights within raw numbers:

Profit-and-loss statement: A furniture retailer thinks it’s performing well until its CFO converts its income statement into percentages. While its 40% gross margin looked healthy, employee costs accounted for 32% of revenue – nearly 10% higher than the industry average. This information might convince the retailer to restructure its staffing to reduce annual costs.
Balance sheet: A manufacturing firm can’t explain its struggles with cash flow despite strong sales. Its standard size balance sheet revealed that inventory represented 45% of total assets, exceeding its competitors’ average by close to 20%. This could indicate that the company is sitting on months of excess materials, tying up working capital.
Cash flow statement: A financial analyst reviewing a tech start-up’s percentages discovers that operating activities generated only 10% of its cash. Financing provided 60%, highlighting the company’s potentially dangerous dependence on investors rather than business operations.

Pros and cons of common size analysis

Common size analysis standardises financial figures to make it easier to draw insight from numbers. But, as with any financial tool, it has strengths and limitations that financial professionals should know.

Advantages of common size analysis

Makes size irrelevant: Enables direct comparison between a $5 million business and a $5 billion corporation.
Reveals structural shifts: Quickly identifies when expenses grow disproportionately to revenue.
Simplifies communication: Helps non-financial stakeholders grasp a company’s financial structure through percentages.
Supports benchmarking: Creates a standardised view for industry comparisons, competitor analysis and internal targets.

Limitations and pitfalls

Hides real impact: A small percentage change in a big company can still mean millions of dollars.
Ignores economic context: Percentages don’t account for inflation, market conditions or industry disruptions.
Can mask timing issues: For seasonal businesses, comparing different months or quarters may skew the accurate picture.
Requires quality data: Inconsistent accounting practices between competitors can make results misleading.
Not a standalone tool: Most effective when combined with other analyses, such as cash flow and liquidity assessments.

Did you know?

Most public company CFOs present common-size analysis in quarterly earnings reports because SEC regulations require them to explain material changes in financial structure, and percentage shifts offer the clearest indication of structural movement regardless of company growth.

How Workday supports common size financial analysis

Workday Adaptive Planning turns common size analysis into a streamlined insight engine. The built-in tools help finance teams quickly standardise financial data for meaningful comparisons.

The solution includes:

Self-service analytics and reporting: Enable confident decisions with intuitive self-service reporting and powerful interactive analytics.
Drag-and-drop report builder: Configure reports to meet your needs by using an intuitive report builder and formula wizard.
Interactive comparison dashboards: See raw numbers and percentages together on dashboards or reports across time, teams or companies.
Seamless Integrations: Connect to Google and Microsoft apps to create highly formatted reports. Drill into summary data to see details in real time.
Mitigate risks, seize opportunities: Identify problem areas, and evaluate unlimited forecast scenarios to address issues.

See your financial insights in action. Watch a quick demo of Workday Adaptive Planning to discover how percentage-based analysis can transform your financial decision-making.

Putting common size analysis into action

Effective FP&A teams help leaders make informed decisions using holistic data analysis. Common size analysis is a crucial part of this process, revealing structural insights that go deeper than revenue and other surface-level numbers.

Don’t wait for annual reviews to complete common size analysis. Track these percentages monthly to catch margin slips, expense creep and other financial shifts early on. When possible, compare your percentages against other percentages to highlight gaps and potential improvement opportunities.

Finance software generates these percentage views automatically to avoid manual errors. It’s easier than ever to yield actionable insights when you examine the story your percentages tell from common-size analysis.