Rounding Calculator (Decimals, Half Even, Up, Down)
Enter a number, the decimal places and the rounding rule.
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Rounding Calculator (Decimals, Half Even, Up, Down) by TheCalcTools
How the Rounding Calculator (Decimals, Half Even, Up, Down) works
Rounding to p decimal places keeps p digits after the point. Halves can go away from zero (2.345 → 2.35, the school rule) or to the nearest even digit (2.345 → 2.34), which avoids bias in long sums and is the IEEE 754 default.
Computers store decimals in binary, so 2.345 is really 2.34499999…; this calculator treats values within a billionth of a half as exact halves, as people expect.
The formula
Worked example
Using the default values shown in the calculator:
| Number | 2.345 |
|---|---|
| Decimal places (negative for tens, hundreds…) | 2 |
| Rule | Nearest, halves away from zero |
| Or round to a multiple of | 0.05 |
- 2.345 to 2 places, halves away from zero: 2.35.
- To the nearest 0.05: 2.35.
Result:
| Rounded | 2.35 |
|---|---|
| Rounded to the multiple | 2.35 |
| Change | 0.0050 |
Frequently asked questions
Why does banker's rounding exist?
Always rounding halves up adds a small upward bias over many values. Rounding halves to even balances up and down.
How do I round to the nearest 5 cents?
Use the multiple field with 0.05.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.