Rounding Calculator
Round any number to the nearest whole, tenth, hundredth, ten, hundred, or thousand — half-up, banker's rounding, ceiling, floor, or truncate.
Round any number to the nearest whole, tenth, hundredth, ten, hundred, or thousand — half-up, banker's rounding, ceiling, floor, or truncate.
Round to cents correctly — and see how half-up versus banker's rounding differ on .5 cases.
Round to significant figures or decimal places consistently across a whole report.
Match your answer to the "round to 2 decimal places" instruction exactly.
Round calculated dimensions to what your tape measure or tools can actually cut.
Rounding halves to the nearest even number stops a long column of figures drifting steadily upward. It is the default in accounting and in most programming languages.
Countries that withdrew their smallest coin round cash totals to the nearest five, while card payments stay exact — so the same basket can cost two different amounts.
Look at the digit immediately to the right of the place you are rounding to. If it is 5 or more, round the target digit up; if it is 4 or less, keep it and drop the rest. Examples: 3.14159 → 3 (nearest whole), 3.1 (nearest tenth), 3.14 (nearest hundredth). For tens/hundreds, the same rule applies to the left of the decimal: 1,847 → 1,850 (nearest ten) → 1,800 (nearest hundred).
When a value is exactly halfway (e.g. 2.5 or 3.5), banker's rounding rounds to the nearest even digit: 2.5 → 2, 3.5 → 4. Regular half-up rounding always pushes .5 upward, which introduces a small systematic upward bias when summing many rounded values. Banker's rounding cancels that bias, which is why it is the default in IEEE 754 floating-point arithmetic, Python's round(), and many financial systems.
Rounding goes to the nearest value by rule. Ceiling always goes up to the next multiple (3.01 → 4), floor always goes down (3.99 → 3), and truncation simply cuts off digits toward zero (−3.7 → −3, where floor would give −4). Ceiling is used for "how many containers do I need" problems; floor for "how many complete units fit"; truncation is common in programming integer conversion.
Rounding too early compounds errors: rounding each line of an invoice before summing can differ from rounding the final total by several cents — which is why accounting standards specify when to round. In engineering and statistics, keep full precision through intermediate steps and round only the final result to the appropriate number of significant figures.