How to Calculate Profit Margin: Gross, Operating and Net

Profit margin is a profit figure divided by net sales, shown as a percentage. There are three common levels, one for each profit line on the income statement. Gross margin is gross profit ÷ net sales. Operating margin is operating income ÷ net sales. Net margin is net income ÷ net sales. OpenStax describes profit margin as how much "of sales revenue has translated into income."

Billed publishes this page. Definitions are quoted from the open textbooks OpenStax Principles of Finance 2e (published June 24, 2026; pages revised July 6, 2026) and OpenStax Introduction to Business 2e (published April 22, 2026; pages revised April 23, 2026), opened on October 30, 2026.

The three profit lines

Each margin starts from a line on the income statement:

• Gross profit: net sales minus the cost of goods sold. The gross profit guide covers what goes into each.
• Operating income: OpenStax says: "After gross profit is calculated, other operating expenses are deducted in order to calculate the firm’s income from operations, also commonly called operating income."
• Net income: OpenStax says: "The most common items deducted from operating income to arrive at net income include interest expense, gains/losses, and income tax expense."

The formulas

• Gross margin: OpenStax describes it as "gross profit divided by net sales".
• Operating margin: operating income ÷ net sales. OpenStax gets each percentage the same way: "A common-size income statement is created by restating each line as a percentage of net sales." Operating margin is the operating income line restated that way.
• Net margin: OpenStax says: "The ratio of net profit to net sales is the net profit margin, also called return on sales." It adds: "It measures the percentage of each sales dollar remaining after all expenses, including taxes, have been deducted." For how return on sales is read, see what is return on sales.

Multiply each result by 100 to show it as a percentage.

Sample: three margins from one year

The figures here are a sample, invented for this example. A design studio's income statement for the year shows:

1. Net sales: $200,000
2. Cost of goods sold (direct labor and materials on client work): $90,000
3. Gross profit: $200,000 − $90,000 = $110,000
4. Operating expenses (rent, software, admin salaries): $70,000
5. Operating income: $110,000 − $70,000 = $40,000
6. Interest expense: $2,000 and income tax expense: $8,000
7. Net income: $40,000 − $2,000 − $8,000 = $30,000

The margins:

• Gross margin: $110,000 ÷ $200,000 = 0.55, or 55%
• Operating margin: $40,000 ÷ $200,000 = 0.20, or 20%
• Net margin: $30,000 ÷ $200,000 = 0.15, or 15%

In this sample, each step down the income statement removes another group of costs, so each margin is lower than the one before.

Profit margin and contribution margin

Profit margins use totals from the income statement. Contribution margin uses each unit's selling price minus its variable costs, and it's used for questions such as break-even. See what is contribution margin.

Where Billed fits

Billed's financial reporting page says: "See how profitable your business is with Income vs Expense report." It also says: "Billed offers several built-in reports: Invoice Reports (paid, partially paid, and overdue), Expense Reports, Income vs Expense Reports, Top Selling Products, and Time Tracking Reports." Use your income statement figures for the margin formulas above, and ask your accountant how your costs should be grouped.

Related Articles

• What is Gross Profit? A Simple Guide for Small Business
• What Is Contribution Margin? A Simple Guide for Small Business

Frequently Asked Questions

What is profit margin?

OpenStax says: "Profit margin represents how much of sales revenue has translated into income." It's a profit figure divided by net sales.

How do you calculate gross margin?

Divide gross profit by net sales. OpenStax describes it as "gross profit divided by net sales". In this page's sample, $110,000 ÷ $200,000 = 55%.

How do you calculate net profit margin?

OpenStax says: "The ratio of net profit to net sales is the net profit margin, also called return on sales." In this page's sample, $30,000 ÷ $200,000 = 15%.

What is the difference between gross margin and operating margin?

Operating margin also takes off operating expenses. OpenStax says: "After gross profit is calculated, other operating expenses are deducted in order to calculate the firm’s income from operations, also commonly called operating income."

Is net profit margin the same as return on sales?

Yes. OpenStax says the net profit margin is "also called return on sales."