A debit is an entry on the left side of an account and a credit is an entry on the right side — they are directions, not plus and minus. Whether that entry increases or decreases the account depends on where the account lives in the accounting equation: assets and expenses grow with debits, while liabilities, equity, and revenue grow with credits. Every transaction records at least one debit and one credit, and the two totals are always equal.
That last sentence is the whole reason the system exists. Double-entry bookkeeping, in use since before Luca Pacioli documented it in 1494, checks itself: because every entry posts equal debits and credits, total debits across all accounts must equal total credits. If they ever differ, you have found an error before you even know what the error is.
The trouble is that everyday English fights you. Outside accounting, credit sounds like money arriving and debit sounds like money leaving, so most students start by assuming credit means add and debit means subtract. Accounting makes no such promise. Debit and credit only tell you which side of the account an entry goes on; the account's type tells you what that side does.
Start from the accounting equation: Assets = Liabilities + Equity. Assets sit on the left of the equals sign; liabilities and equity sit on the right. The debit-and-credit convention mirrors that geography: an account keeps its normal balance on the same side of the ledger that it occupies in the equation.
This is why the rules are not arbitrary. If a business borrows cash, its assets grow (debit Cash) and its liabilities grow (credit Notes Payable). One left-side account and one right-side account both increase, so the equation stays balanced because the entry itself is balanced.
Revenue and expenses follow from equity. Revenue makes the owner's claim bigger, so it behaves like equity and grows with credits. Expenses make the owner's claim smaller, so they run in reverse and grow with debits — a debit to Rent Expense is really a small reduction of equity, tracked in its own account so you can see where the money went. Writing the equation in its expanded form makes every rule visible at once.
Assets + Expenses + Draws = Liabilities + Equity + Revenue
Assets — Resources the business owns (cash, equipment, receivables). Left side — grows with debits.
Expenses — Costs of operating (rent, wages, supplies used). Left side — grows with debits.
Draws — Amounts the owner takes out (dividends in a corporation). Left side — grows with debits.
Liabilities — Amounts the business owes (payables, loans). Right side — grows with credits.
Equity — The owner's residual claim on the assets. Right side — grows with credits.
Revenue — Amounts earned from customers. Right side — grows with credits.
Everything on the left of the expanded equation has a normal debit balance; everything on the right has a normal credit balance. A normal balance is nothing deeper than the side an account grows on. There is no chart left to memorize — if you can place an account in the equation, you know its side.
| Account type | Increases with | Decreases with | Normal balance |
|---|---|---|---|
| Assets | Debit | Credit | Debit |
| Expenses | Debit | Credit | Debit |
| Liabilities | Credit | Debit | Credit |
| Equity | Credit | Debit | Credit |
| Revenue | Credit | Debit | Credit |
For any transaction, ask two questions in order. First, which accounts did this touch? Every transaction touches at least two. Second, did each account grow or shrink? Growth goes on the account's normal side; shrinkage goes on the opposite side. The debits and credits then assign themselves. Students who guess are usually skipping the first question and trying to jump straight from "money moved" to a side.
Watch the habit decide six ordinary transactions for a new campus coffee cart.
| Transaction | Debit account | Credit account | Amount |
|---|---|---|---|
| Owner invests savings to start the business | Cash | Owner's Capital | $9,400 |
| Buys an espresso machine, paying cash | Equipment | Cash | $3,180 |
| Buys beans and cups on account | Supplies | Accounts Payable | $742 |
| Sells drinks for cash during the week | Cash | Sales Revenue | $1,265 |
| Pays the month's stall rent | Rent Expense | Cash | $850 |
| Pays down part of the supplier bill | Accounts Payable | Cash | $410 |
Walk through three of those rows with the two-question habit.
In the first row, the business received $9,400 of cash and the owner's claim on the business grew by the same amount. Cash is an asset growing, so it is debited; Owner's Capital is equity growing, so it is credited.
The rent payment in row five touches Cash and Rent Expense. Cash is an asset shrinking, so it is credited — the opposite of its normal side. Rent Expense is an expense growing, and expenses grow with debits because each expense quietly reduces equity.
Row six is the one that breaks the "credit means add money" instinct. Paying $410 to the supplier shrinks Cash (credit) and shrinks Accounts Payable (debit). A liability decreased, and decreases post to the opposite of the normal side — so the debit here records a reduction. If you can explain why Accounts Payable is debited in that row, the rules have clicked. Notice that you never asked whether anything was positive or negative; you only asked what grew, what shrank, and where each account lives in the equation.
The most common wrong turn is treating debit and credit as synonyms for minus and plus. They are locations. A debit increases Cash in row one and decreases Accounts Payable in row six, under the same rule. The confusion is usually planted by bank statements: your bank credits your account when you deposit money. That statement is written from the bank's books, where your balance is money the bank owes you — a liability. The bank credits its liability because the liability grew. On your own books, the same deposit is a debit to Cash. Same event, opposite labels, because the two parties hold mirror-image accounts.
Mnemonics like DEALER or DEAD CLIC can carry you through one quiz, but they fail the moment an unfamiliar account appears, because a letter string has no way to classify Unearned Revenue or Prepaid Insurance. The equation does. Unearned Revenue is a liability — you owe the customer work — so it grows with credits. Prepaid Insurance is an asset — a resource you have paid for and not yet used — so it grows with debits. Place the account first; the side follows. Use a mnemonic as a speed check if you like, but be able to rebuild the rule from the equation in ten seconds.
Some accounts deliberately carry the opposite balance of their section. Accumulated Depreciation sits with the assets on the balance sheet but holds a credit balance, because its job is to offset the asset it is paired with — the espresso machine stays on the books at its $3,180 cost while the offset grows each period. Allowance for Doubtful Accounts and Sales Returns work the same way. Contra accounts are not exceptions to the rule; they record subtractions from a partner account, so their normal balance is the reverse of their neighbors'. When you see a wrong-sided balance, ask what that account is subtracting from.
Debit means left and credit means right — nothing more. Accounts on the left of the expanded accounting equation (assets, expenses, draws) grow with debits; accounts on the right (liabilities, equity, revenue) grow with credits; decreases go on the opposite side. Place the account in the equation and the side chooses itself.
A debit is an entry on the left side of an account; a credit is an entry on the right side. Neither means increase or decrease on its own — the effect depends on the account type. Debits increase assets and expenses; credits increase liabilities, equity, and revenue.
It depends on the account. A debit increases assets and expenses but decreases liabilities, equity, and revenue. Paying off part of a loan, for example, is recorded as a debit to the loan account because the liability shrank.
The statement is written from the bank's point of view. Your balance is money the bank owes you — a liability on the bank's books — so a deposit grows that liability and the bank credits it. On your own books, the same deposit is a debit to Cash.
Only loosely, through banking terminology. A debit card pulls money directly from your bank account; a credit card creates a liability you settle later. Neither changes how debits and credits work in a ledger, and the card meanings cause enough confusion that it is safer to set them aside while studying accounting.
Yes. Every journal entry posts equal debit and credit amounts, so the totals across all accounts must match. A trial balance where they differ signals a recording error, such as posting only half an entry or transposing digits.
Assets, expenses, and owner's draws or dividends — the left side of the expanded accounting equation. Contra accounts are the mirror-image cases: Accumulated Depreciation sits in the asset section but carries a normal credit balance because it offsets an asset.
By the FinanceBrain Team · Last verified July 10, 2026 · How we produce and verify articles