The accounting equation is Assets = Liabilities + Equity. It states that everything a business owns was financed by one of two sources: money the business owes to outsiders, or money that belongs to its owners. The two sides are always equal because every transaction is recorded twice — once for the resource that changed, and once for the claim on it.
That double recording is the point of the equation, not a happy side effect. Double-entry bookkeeping forces you to answer two questions about every event: what did the business get or give up, and who has a claim on it now? Record both answers and the totals cannot drift apart. So when a trial balance is off, the equation has not failed — a transaction was recorded on one side only, or at two different amounts, and the imbalance is telling you where to look.
The equation is also the skeleton of the balance sheet. Assets sit on one side; liabilities and equity sit on the other. When a balance sheet balances, that is this equation holding at a single point in time — which is why instructors keep returning to it long after the first week of the course.
Assets are resources the business owns or controls that are expected to provide future benefit. Cash is the obvious one, but the category is wider: accounts receivable (a customer's promise to pay is a resource, even though no cash has arrived yet), supplies, inventory, equipment, buildings, and prepaid expenses all qualify. The test is control plus expected future benefit — not whether the item is physical, and not whether it was paid for in cash.
Liabilities are amounts the business owes to people who are not its owners: accounts payable to suppliers, notes payable to a bank, wages payable to employees, taxes payable to the government. One that surprises students is unearned revenue — cash a customer paid in advance. It counts as a liability because the business now owes that customer a product or service, not because it owes the money back.
Equity is the owners' residual claim: whatever is left of the assets after every outside claim is satisfied. Rearranged, the same equation reads Equity = Assets − Liabilities, which is why equity is sometimes called net assets. Equity grows when owners contribute capital and when the business earns profit; it shrinks when the business distributes money to owners (drawings or dividends) and when it runs at a loss.
Two things equity is not. It is not a pile of cash sitting in an account somewhere — it is a claim against the assets as a whole. And it is not frozen at whatever the owner originally invested — every profitable period quietly increases it, and every loss reduces it.
The fastest way to make all of this concrete is to watch the equation absorb a series of transactions and stay balanced the whole way through.
| Transaction | Assets | Liabilities | Equity |
|---|---|---|---|
| 1. Maya invests $18,500 cash to start the business | $18,500 | $0 | $18,500 |
| 2. Buys $7,200 of equipment: $2,700 cash plus a $4,500 note payable | $23,000 | $4,500 | $18,500 |
| 3. Buys $1,340 of supplies on account | $24,340 | $5,840 | $18,500 |
| 4. Earns $3,150 of service revenue, collected in cash | $27,490 | $5,840 | $21,650 |
| 5. Pays $900 to the supplier from transaction 3 | $26,590 | $4,940 | $21,650 |
A few rows deserve a second look. In transaction 2, assets rose by only $4,500 even though Maya bought $7,200 of equipment — $2,700 of cash left the business at the same moment, so part of the entry was a swap of one asset for another. In transaction 4, the revenue does not get its own column; it lands in equity, because profit belongs to the owner. And in transaction 5, both sides of the equation shrink together: paying a debt uses up an asset and removes a claim in the same stroke.
This running-total format is worth copying for homework. Before you touch debits and credits, name each transaction's two effects and check that the totals still agree — it catches half-recorded entries early. The equation also solves for missing figures directly: a problem that gives you total assets of $412,780 and total liabilities of $167,300 is really asking you to subtract, and equity of $245,480 falls out.
Revenue is not a new bucket sitting next to assets, liabilities, and equity. Earning revenue increases equity, and incurring an expense decreases it. The expanded accounting equation makes this visible: Assets = Liabilities + Contributed capital + Revenues − Expenses − Drawings. Every income statement account is a temporary subdivision of equity, which is why closing entries fold them all back into it at the end of the period.
Debits and credits are directions — left and right — not signs. A debit increases an asset but decreases a liability; a credit does the opposite. Students who memorize debit means down get stuck the first time they debit cash and the balance goes up. Anchor the rules to the equation instead: accounts on the left side (assets) grow with debits, and accounts on the right side (liabilities and equity) grow with credits. Expenses and drawings grow with debits precisely because they reduce equity, a right-side account.
In the table above, Maya's equity ends at $21,650 while her cash is a different number entirely — she has spent some and tied some up in equipment and supplies. Equity is a claim on all the assets collectively; it does not correspond to any account you could withdraw from. A business can carry large equity and almost no cash, profitable but illiquid, and the equation is the cleanest way to see how that happens.
A related trap: withdrawals. When Maya takes money out for herself, that is a drawing — it reduces equity directly. It is not an expense, because it is not a cost of earning revenue, so it never touches the income statement.
Assets = Liabilities + Equity holds after every single transaction, not just at year end. If your running totals ever stop matching, a transaction was recorded on one side only — find that entry before you move on.
Assets = Liabilities + Equity. It is also called the fundamental accounting equation or the balance sheet equation — all three names refer to the same identity: a business's resources equal the claims against them.
The expanded form breaks equity into its moving parts: Assets = Liabilities + Contributed capital + Revenues − Expenses − Drawings (a corporation would say common stock, retained earnings, and dividends). It says nothing new about the business — it shows why equity changed during the period.
Because every transaction is recorded with two equal effects — the dual aspect concept behind double-entry bookkeeping. A transaction either changes both sides by the same amount or changes one side twice in offsetting directions. There is no third option, so the totals cannot diverge unless an entry was recorded wrong.
Yes. The balance sheet is the accounting equation presented as a financial statement: assets on one side, liabilities and equity on the other, at a single date. If a balance sheet does not balance, some entry behind it broke the equation.
Equity, also called net assets or book value. Rearranging the equation gives Equity = Assets − Liabilities: what the owners would keep, on paper, if every asset were converted at its recorded value and every debt were paid.
By the FinanceBrain Team · Last verified July 10, 2026 · How we produce and verify articles