Round any number to decimals, significant figures or a place value.
Look at the digit after the place you are rounding to: 5 or more rounds up, 4 or less rounds down. 3.14159 rounded to 2 decimal places is 3.14.
Rounding replaces a number with a simpler one that is close to it. This calculator rounds to a chosen number of decimal places, significant figures, or the nearest ten, hundred, thousand and so on, and shows the result for all seven methods: half up, half down, half to even (banker's rounding), ceiling, floor, truncate and away from zero.
The calculator works on the exact decimal digits you type, so classic cases like 2.675 round to 2.68 correctly, where many programs give 2.67. For very small or large numbers see the Scientific Notation Converter; for significant figures in measurements use the Percent Error Calculator.
The calculator applies the standard method step by step.
| Item | Value |
|---|---|
| Original number | 3.14159 |
| Method | Result |
|---|---|
| Round half up (away from zero at .5) | 3.14 |
| Round half down (toward zero at .5) | 3.14 |
| Round half to even (banker's rounding) | 3.14 |
| Round up (ceiling, toward +∞) | 3.15 |
| Round down (floor, toward −∞) | 3.14 |
| Truncate (toward zero) | 3.14 |
| Round away from zero | 3.15 |
| Rounded to | Result |
|---|---|
| 2 decimal places | 3.14 |
| 0 decimal places | 3 |
| 3 decimal places | 3.142 |
| 3 significant figures | 3.14 |
| Nearest 10 | 00 |
Look at the third decimal digit. If it is 5 or more, increase the second decimal by 1; otherwise leave it. 3.14159 → 3.14.
Any digit that carries meaning about a measurement, starting from the first non-zero digit. 0.00123 has three significant figures.
Round half to even: a 5 rounds to the nearest even number, so 2.5 → 2 and 3.5 → 4. It avoids a consistent upward bias in large sets of data.
For positive numbers they are the same; for negatives, rounding down (floor) goes toward −∞ while truncating goes toward zero.
Look at the digit to the right of that place: 1,234 → 1,230 (nearest 10), 1,200 (nearest 100).
Computers store 2.675 as a binary approximation slightly below 2.675. This calculator works on the exact decimal digits, giving the answer taught in school.
It uses the standard method: round half up: look at the next digit — 5–9 rounds up, 0–4 rounds down The full working and a worked example are shown on this page.
Decimal results use standard double-precision arithmetic (about 15–16 significant digits). Tools that work with whole numbers — big numbers, factors, bases, combinations — use exact integer arithmetic, so no digits are lost.
Yes for checking your work and learning the method. The steps and formula are shown so you can understand the answer, but follow your teacher's rules about calculators in exams.
No. Everything is calculated in your browser and nothing you enter is uploaded or saved.
