Understand the fundamental accounting equation, how assets, liabilities and equity are connected, and why every financial transaction must keep the equation in balance.
What Is the Accounting Equation?
The accounting equation is the foundation of double-entry bookkeeping. It shows the relationship between a business’s assets, liabilities and owner’s equity.
The equation means that everything a business owns or controls is financed either through amounts owed to others or through the owner’s interest in the business.
Understanding the Three Elements
1. Assets
Assets are economic resources controlled by a business as a result of past events, from which future economic benefits are expected.
Examples include:
- Money held in business bank accounts
- Equipment and machinery
- Inventory held for sale
- Amounts owed by customers
2. Liabilities
Liabilities are present obligations of the business to transfer economic resources as a result of past events.
Examples include:
- Bank loans
- Outstanding supplier invoices
- Accrued expenses
- Taxes payable
3. Equity
Equity is the residual interest in the assets of a business after deducting its liabilities.
Equity may include capital contributed by owners and accumulated profits retained in the business, less relevant withdrawals or distributions.
Practical Accounting Equation Examples
Example 1: Owner Invests Money
A sole trader starts a business and deposits £5,000 of personal money into the business bank account.
The business’s bank asset increases by £5,000, and the owner’s capital increases by £5,000.
The equation balances because both assets and equity increase by the same amount.
Example 2: Business Takes Out a Loan
The business receives a £2,000 bank loan, paid into its bank account.
Bank assets increase by £2,000, and loan liabilities increase by £2,000.
The loan increases the business’s cash resources, but it does not create revenue or profit.
Example 3: Purchasing Equipment
The business buys equipment for £1,200, paying immediately from its bank account. Ignore VAT.
Equipment assets increase by £1,200, while bank assets decrease by £1,200.
Total assets remain unchanged because one asset has been exchanged for another.
How Transactions Affect the Equation
Different transactions affect different elements of the accounting equation.
| Transaction | Effect on Assets | Effect on Liabilities / Equity |
|---|---|---|
| Owner invests cash | Increase | Equity increases |
| Business receives a loan | Increase | Liabilities increase |
| Equipment purchased for cash | One asset increases; another decreases | No change |
| Supplier bill paid | Decrease | Liabilities decrease |
| Business earns revenue for cash | Increase | Equity increases through profit |
The accounting equation explains the financial effect of transactions, while double-entry bookkeeping provides the method for recording them.
How the Accounting Equation Relates to the Balance Sheet
The balance sheet, also called the statement of financial position, reports a business’s assets, liabilities and equity at a particular date.
Because it follows the accounting equation, total assets must equal total liabilities plus equity.
Common Accounting Equation Mistakes
- Treating a bank loan as business revenue
- Assuming every cash payment is an expense
- Confusing owner contributions with sales
- Forgetting that unpaid supplier bills create liabilities
- Assuming that a balanced equation guarantees every transaction has been recorded correctly
Test Your Knowledge
A business has assets of £15,000 and liabilities of £6,000.
What is the value of its equity?
Click to reveal the answer
Equity = Assets − Liabilities
£15,000 − £6,000 = £9,000
The accounting equation balances:
£15,000 = £6,000 + £9,000