Rounding calculator (5 rounding modes)
Enter a number, choose the decimal places (or significant figures) and the rounding rule. All five rules are shown side by side so you can see the difference.
Result
2.34Rounded number
- Difference (rounded − number)
- -0.005
- Nearest, half up
- 2.35
- Nearest, half to even
- 2.34
- Down (floor)
- 2.34
- Up (ceiling)
- 2.35
- Toward zero (truncate)
- 2.34
Inputs
- Number to round
- 2.345
- Round to
- Decimal places
- Decimal places or figures
- 2
- Rounding rule
- Nearest, half to even (banker’s)
How it is calculated
Nearest: look at the next digit; 5 or more rounds up (in absolute value).
Result
Rounded number
- Difference (rounded − number)
- -0.005
- Nearest, half up
- 2.35
- Nearest, half to even
- 2.34
How it is calculated
- Nearest: look at the next digit; 5 or more rounds up (in absolute value).
- Half to even: an exact 5 goes to the even digit (2.345 → 2.34; 2.355 → 2.36).
- Down and up: always toward smaller or larger numbers on the number line.
- Toward zero: simply drop the extra digits.
Example
2.345 to 2 decimals: 2.35 half up, 2.34 half to even, 2.34 down, 2.35 up, 2.34 toward zero.
Good to know
- Rounding works on the decimal writing of the number: 2.675 does give 2.68.
- For negative numbers, “down” goes toward −∞ and “toward zero” moves closer to 0.
When to use it
- Compare rounding rules for homework or a report.
- Round an amount or measurement to the desired precision.
Frequently asked questions
What is this tool used for?
Enter a number, choose the decimal places (or significant figures) and the rounding rule. All five rules are shown side by side so you can see the difference.
How is the result calculated?
Nearest: look at the next digit; 5 or more rounds up (in absolute value).
What should I check before using the result?
Rounding works on the decimal writing of the number: 2.675 does give 2.68.