Rounding Calculator
Last updated: November 5, 2026
Round a number to a selected number of decimal places and compare floor, ceiling and truncation.
Rounded value
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- Rounded to nearest integer: —
- Rounded down at selected precision: —
- Rounded up at selected precision: —
- Truncated at selected precision: —
On this page
Quick summary: Round a number to a selected number of decimal places and compare floor, ceiling and truncation.
Read the complete guide
Updated reference sections in this guide are in English.
What this calculator estimates
Round a number to a selected number of decimal places and compare floor, ceiling and truncation.
How to use it
Enter Number; Decimal places. Select Calculate to update the results.
How the calculation works
Scale the number by 10 raised to the requested decimal places, apply the selected rounding operation, then scale it back.
Worked example: starting scenario
| Number | 1234.5678 |
|---|---|
| Decimal places | 2 |
| Rounded value | 1,234.57 |
|---|---|
| Rounded to nearest integer | 1,235 |
| Rounded down at selected precision | 1,234.56 |
| Rounded up at selected precision | 1,234.57 |
| Truncated at selected precision | 1,234.56 |
Important limitations
Binary floating-point arithmetic can create tiny representation effects for certain decimal values.
Decimal places and halfway values
Rounding 1,234.567 to two decimal places gives 1,234.57; two significant figures would instead give about 1,200. This form rounds the decimal value entered to 0–12 places. Nearest-rounding ties go toward positive infinity: 1.5 rounds to 2 and −1.5 rounds to −1. Floor goes toward negative infinity, ceiling toward positive infinity, and truncation toward zero.
The entered decimal text is rounded before binary floating-point formatting. Thus 10.075 rounds to 10.08 at two places, with floor and truncation 10.07 and ceiling 10.08. These rules concern numerical rounding; a tax form or contract can specify a different halfway rule.