Rounding Calculator
Round a number to a chosen number of decimal places or significant figures.
Rounded result
How we calculated this
Worked example
3.14159 rounded to 2 decimal places is 3.14.
How it works
This tool rounds a number either to a chosen number of decimal places or to a chosen number of significant figures, using the conventional "round half away from zero" rule: an exact halfway value always rounds outward, away from zero (2.5 rounds to 3, and −2.5 rounds to −3, never towards zero).
Xiliro corrects for a well-known quirk of computer arithmetic. A value like 1.005 can be stored internally as very slightly less than 1.005, which would otherwise cause it to round down instead of up, and this correction is applied consistently regardless of how large or small the number is.
It does not offer unlimited precision: decimal places are limited to 10, and significant figures to 15, beyond which ordinary computer number storage is no longer reliably exact.
What this result means
The result is your number rounded to the number of decimal places, or significant figures, you chose.
Examples
- 12,345 rounded to 3 significant figures: 12,300
Common mistakes
- Significant-figures mode does not pad the display with trailing zeros to show precision — 100 to 5 significant figures is still shown as 100, not 100.00.