A company's sales revenue (also referred to as "net sales") is the income that it receives from the sale of goods or services. For example, if a company charges $300 for a TV and sells 1000 TVs, its sales revenue is $300,000.

On the other hand, gross profit is the income that a company makes from its sales after the cost of the goods and operating expenses have been subtracted. This includes expenses that depend on the company's sales – such as materials, labor costs, equipment, sales commissions, and depreciation that results from production -- all variable costs. It does not include fixed expenses such as rent, insurance, administrative costs, and other expenses that don't directly depend on sales.

Here are some examples of expenses that would and would not be included in calculating gross profit:

Included

Not Included

Materials used to make a product

Office supplies and equipment

Labor costs (for individuals involved in making products)

Labor costs (for office personnel and other non-production employees)

Shipping costs

Advertising costs

Packaging expenses

Rent

Depreciation on facilities and equipment used in production

Insurance expense

Machinery used in production

Employee benefits

To illustrate this, consider the following data from Apple's 2014 income statement:

Metric

Amount ($Billions)

Net Sales (Revenue)

182.8

Cost of Goods Sold

104.3

Depreciation and Amortization

8.0

General and Administrative Expenses

18.0

Research & Development

6.0

Using the above data, in order to calculate the gross profit we need to subtract the cost of goods sold as well as the depreciation and amortization expenses.

Gross Profit Calc

By calculating a company's gross profit, you can use the information to calculate the gross profit margin, which is equal to the gross profit divided by the revenue. This is a good way to determine how efficiently a company is producing its products compared to the rest of its industry, and to its own historical performance.

Gross Profit Margin

So, in the case of our Apple example, the gross profit margin would be equal to $70.5 billion divided by $182.8 billion, or 38.6%.

Be careful not to confuse gross profit with operating profit, which is a better indicator of the overall profitability of a company. In addition to accounting for the cost of goods, operating profit subtracts the company's operating expenses and expenses associated with developing new products. When evaluating the profitability of a business, bear in mind that it is entirely possible for a company to produce strong gross profits, but to still operate at a loss because of high fixed expenses.

This article is part of The Motley Fool's Knowledge Center, which was created based on the collected wisdom of a fantastic community of investors. We'd love to hear your questions, thoughts, and opinions on the Knowledge Center in general or this page in particular. Your input will help us help the world invest, better! Email us at knowledgecenter@fool.com. Thanks -- and Fool on!

Matthew Frankel has no position in any stocks mentioned. The Motley Fool owns and recommends Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.