Why the bottom line matters to a first-time founder
On an income statement the bottom line is usually net profit, the amount left after income and expenses have been counted. People also use the phrase for the final point of a decision, with no number attached. Others use it loosely for operating profit. If you do not ask which meaning is in play, you can treat a figure that still faces interest and tax as the result.
Examples of the bottom line
An importer in Wellington shows revenue of NZD 1.2 million, operating profit of NZD 90,000, and net profit of NZD 35,000 after interest and tax. A manager calls NZD 90,000 the bottom line because the trading operation made that much. That figure is operating income under another name. On the income statement the bottom line is the NZD 35,000. The two figures answer different questions.
Common misunderstanding
The bottom line is not revenue, not gross profit, and not automatically operating profit. Those lines sit higher on the income statement. In ordinary speech the phrase can mean the practical conclusion and refer to no profit figure at all. When money is meant, ask whether the speaker means net profit after interest and tax.
When to use it
Use it for net profit, and say net profit as well, so nobody substitutes operating profit. In a conversation that is not about the income statement, do not assume the phrase points at a number in the accounts.