||The lead section of this article may need to be rewritten. The reason given is: Needs a simple opening paragraph explaining what the accounting equation is and why someone might want to use it.. (September 2012)|
The basic accounting equation, also called the balance sheet equation, represents the relationship between the assets, liabilities, and owner's equity of a business. It is the foundation for the double-entry bookkeeping system. For each transaction, the total debits equal the total credits. It can be expressed as
In a corporation, capital represents the stockholders' equity. Since every business transaction affects at least two of a company’s accounts, the accounting equation will always be “in balance,” meaning the left side should always equal the right side. Thus, the accounting formula essentially shows that what the firm owns (its assets) is purchased by either what it owes (its liabilities) or by what its owners invest (its shareholders equity or capital).
In practice 
For example: A student buys a computer for $945. This student borrowed $500 from his friend and spent another $445 earned from his part-time job. Now his assets are worth $945, liabilities are $500, and equity $445.
The formula can be rewritten:
- Assets - Liabilities = (Shareholders' or Owners' Equity)
Now it shows owners' interest is equal to property (assets) minus debts (liabilities). Since in a corporation owners are shareholders, owner's interest is called shareholders' equity. Every accounting transaction affects at least one element of the equation, but always balances. Simplest transactions also include:
|1||+||6,000||+||6,000||Issuing stocks for cash or other assets|
|2||+||10,000||+||10,000||Buying assets by borrowing money (taking a loan from a bank or simply buying on credit)|
|3||−||900||−||900||Selling assets for cash to pay off liabilities: both assets and liabilities are reduced|
|4||+||1,000||+||400||+||600||Buying assets by paying cash by shareholder's money (600) and by borrowing money (400)|
|6||−||200||−||200||Paying expenses (e.g. rent or professional fees) or dividends|
|7||+||100||−||100||Recording expenses, but not paying them at the moment|
|8||−||500||−||500||Paying a debt that you owe|
|9||0||0||0||Receiving cash for sale of an asset: one asset is exchanged for another; no change in assets or liabilities|
This equation is part of the transaction analysis model, for which we also write
- Owners equity = Contributed Capital + Retained Earnings
- Retained Earnings = Net Income − Dividends
- Net Income = Income − Expenses
The equation resulting from making these substitutions in the accounting equation may be referred to as the expanded accounting equation, because it yields the breakdown of the equity component of the equation.
Financial Statements 
A company’s quarterly and annual reports are basically derived directly from the accounting equations used in bookkeeping practices. These equations, entered in a business’s general ledger, will provide the material that eventually makes up the foundation of a business’s financial statements. This includes expense reports, cash flow, interest and loan payments, salaries, and company investments.
Double Entry Bookkeeping System 
The accounting equation plays a significant role as the foundation of the double entry bookkeeping system. This accounting system ensures that a company’s accounts are always balanced and that all financial transactions are documented in detail. The primary aim of the double entry system is to keep track of debits and credits, and ensure that the sum of these always matches up to the company assets, a calculation carried out by the accounting equation.
Income and Retained Earnings 
Use of the accounting equation is also an essential component in computing, understanding, and analyzing a firm’s income statement. This statement reflects profits and losses that are themselves determined by the calculations that make up the basic accounting equation. In other words, this equation allows businesses to determine revenue as well as prepare a statement of retained earnings. This then allows them to predict future profit trends and adjust business practices accordingly. Thus, the accounting equation is an essential step in determining company profitability.
Company Worth 
Since the balance sheet is founded on the principles of the accounting equation, this equation can also be said to be responsible for estimating the net worth of an entire company. The fundamental components of the accounting equation include the calculation of both company holdings and company debts; thus, it allows owners to gauge the total value of a firm’s assets.
Due to its role in determining a firm’s net worth, the accounting equation is an important tool for investors looking to measure a company’s holdings and debts at any particular time, and frequent calculations can indicate how steady or erratic a business’s financial dealings might be. This provides valuable information to creditors or banks that might be considering a loan application or investment in the company.
Expanded Accounting Equation 
The expanded Accounting Equation using all five types of accounting elements is:
- Assets + Expenses = Equity + Revenue + Liability
One might also see it in other forms using other domain-specific terminology:
- Assets = Liabilities + Stockholders' Equity
- Assets = Liabilities + Common Stock + Retained Earnings
- Assets = Liabilities + Capital - Drawing + Revenue - Expenses
- Assets = Liabilities + Common Stock + Net Income - Dividends
- Assets = Liabilities + Common Stock + Income - Expenses - Dividends
Balance sheet 
An elaborate form of this equation is presented in a balance sheet which lists all assets, liabilities, and equity, as well as totals to ensure that it balances.
- Meigs and Meigs. Financial Accounting, Fourth Edition. McGraw-Hill, 1983. pp.19-20.
- Accounting equation explanation with examples, accountingcoach.com.
- Libby, Libby, and Short. Financial Accounting, Third Edition. McGraw-Hill, 2001. p.120
- Wild.Financial Accounting, Third Edition.McGraw-Hill, 2005. p.13
- "Accounting Equation". Retrieved 30 April 2013.