BYTETOOLS

Rounding Calculator

Round any number to decimal places, significant figures or the nearest multiple, with round, floor and ceiling modes. Free online rounding calculator.

3.14
Rounded to 2 decimal places

Rounded value

3.14

  • Round to decimal places or significant figures
  • Round to the nearest multiple of any value
  • Round, floor and ceiling directions
  • Shows exactly which rule was applied
  • One-click copy of the result
  • Fast, private, browser-based rounding

How to use the Rounding Calculator

  1. 1

    Enter the number you want to round.

  2. 2

    Choose a mode: decimal places, significant figures or nearest multiple.

  3. 3

    Pick a direction: round, floor or ceiling.

  4. 4

    Set the number of places, figures or the multiple value.

  5. 5

    Read and copy the rounded result.

About the Rounding Calculator

The ByteTools Rounding Calculator rounds any number the way you need it: to a set number of decimal places, to a number of significant figures, or to the nearest multiple such as 5, 10 or 0.25. Each mode also lets you choose to round to nearest, round down (floor) or round up (ceiling).

It is useful for students learning significant figures, engineers working to tolerances, and anyone tidying up messy decimals or pricing to the nearest cent. The result and the rounding rule applied are both shown so there is no ambiguity about what happened.

All rounding is performed locally in your browser with JavaScript. Nothing you type is uploaded or stored, and you can copy the rounded value to your clipboard in a single click.

Frequently asked questions

What is the difference between decimal places and significant figures?

Decimal places count digits after the decimal point, so 3.14159 to two places is 3.14. Significant figures count all meaningful digits from the first non-zero one, so 3.14159 to two significant figures is 3.1, and 0.00456 is 0.0046.

How do you round to the nearest multiple?

Divide the number by the multiple, round to a whole number, then multiply back. For example, rounding 23 to the nearest 5 gives 25, and rounding a price to the nearest 0.05 snaps it to the closest five cents. The tool does this in one step.

What is the difference between floor and ceiling?

Floor always rounds down toward negative infinity, while ceiling always rounds up toward positive infinity. Rounding 4.2 with floor gives 4 and with ceiling gives 5. The default 'round' mode instead goes to whichever is nearest.

How does rounding handle a value exactly halfway?

The nearest-rounding mode uses the common rule of rounding halves up, so 2.5 becomes 3. If you always want the lower or higher value at the halfway point, switch to the floor or ceiling direction instead.

Why do significant figures matter?

Significant figures communicate how precise a measurement is, which is essential in science and engineering. Reporting too many digits implies false accuracy, so rounding to the right number of significant figures keeps results honest.

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