Use this calculator to round any number to decimal places, an integer, or significant figures. Choose the rounding mode you want and see the automatically generated examples.
Rounding Calculator
| Number | Rounded |
|---|
How to Use the Calculator
- Enter the number you want to round.
- Under Round to, choose between: Whole number, Decimal places, or Sig. figs. (significant figures).
- If you chose Decimal places or Sig. figs., enter the desired quantity.
- The Result is updated automatically.
- Check Show advanced rounding modes to choose from Round up, Round down, Half up, and more.
Rounding Rules
The standard rounding ("half up") follows this rule:
- If the digit after the desired position is less than 5, keep the previous digit (round down).
- If it is 5 or greater, increment the previous digit (round up).
Examples with 2 decimal places:
| Number | Mode | Result |
|---|---|---|
| 3.456 | Half up | 3.46 |
| 3.454 | Half up | 3.45 |
| 3.455 | Round up | 3.46 |
| 3.455 | Round down | 3.45 |
| −3.455 | Ceiling | −3.45 |
| −3.455 | Floor | −3.46 |
Rounding by Significant Figures
When rounding to n significant figures, count n digits from the first non-zero digit of the number.
| Number | Sig. figs. | Result |
|---|---|---|
| 0.004567 | 2 | 0.0046 |
| 1.2345 | 3 | 1.23 |
| 12345 | 4 | 12350 |
| 0.09876 | 2 | 0.099 |
Frequently Asked Questions
What is number rounding?
Rounding is the process of simplifying a number by replacing it with another of approximately equal value but with fewer digits. For example, 3.7 rounded to the nearest integer is 4.
How do I round to decimal places?
Look at the digit immediately after the last desired decimal place. If it is 5 or greater, increment the last kept digit; otherwise, drop the remaining digits. Example: 3.456 with 2 decimal places → 3.46.
What are significant figures?
Significant figures are the digits that express the precision of a measurement. Count from the first non-zero digit. Example: 0.004567 with 2 sig. figs. → 0.0046.
What is the difference between Round up and Ceiling?
Round up rounds away from zero (positive → ceiling, negative → floor). Ceiling always moves toward positive infinity regardless of sign. For positive numbers they are equivalent; for negative numbers they differ.
See also…
