Round to the Nearest Hundredth
Round any valid decimal number to two places using the standard half-up rule.
Number to round
Required. Use a decimal point; scientific notation is accepted. Up to 15 significant digits.
A 5 in the thousandths place is a tie and rounds away from zero under the half-up rule.
Live result
Rounding audit
| Step | Value | Meaning |
|---|---|---|
| 1. Original | 1.625 | The validated input value. |
| 2. Keep through hundredths | 1.62 | The provisional value before applying the deciding digit. |
| 3. Inspect thousandths | 5 | A digit of 5 or more triggers a round up. |
| 4. Final result | 1.63 | The value rounded to exactly two decimal places. |
The audit table is generated from the same canonical model used by the result cards and the Excel workbook.
How to use the round to the nearest hundredth calculator
What this calculator does
This calculator rounds one decimal number to the nearest hundredth, so the result contains two digits after the decimal point. It uses the familiar half-up rule: inspect the thousandths digit, keep the hundredths digit when the thousandths digit is 0 through 4, and increase the hundredths digit when it is 5 through 9. The tool performs a numerical rounding operation; it does not determine whether two decimal places are appropriate for the accuracy, uncertainty, or significant figures of a real-world measurement.
When to use it
Use it when checking homework, presenting a calculated measurement to two decimal places, standardizing values before comparison, or verifying a carry such as 4.9962 becoming 5.00. The Open University's explanation of rounding by decimal place provides additional place-value context.
How to calculate
- The calculator opens with the demonstration value 1.625, its live result, and an immediately available example XLSX workbook.
- Replace the value in Number with the decimal you want to round. Use a period as the decimal separator. A leading plus or minus sign and scientific notation such as 1.25e3 are accepted.
- Read Rounded value first, then use Hundredths digit, Thousandths digit, Truncated to hundredths, and the Rounding audit table to verify the decision.
- Select Download Excel to export the current validated input, result, and calculation steps as a genuine XLSX workbook.
- Select Reset to clear the demonstration and calculated content. Reset may disable Download Excel until a complete valid Number is entered again.
Input guide
Number is required. Enter a finite decimal value using U.S.-style notation, with an optional sign and optional exponent. Examples include 18.194, -1.625, .556, and 2.5e-3. Commas and unsupported symbols are rejected rather than silently reinterpreted. Up to 15 significant digits are accepted so exported numeric cells remain reproducible in common spreadsheet software. The sign does not change the digit test, but an exact tie for a negative number rounds away from zero. A common mistake is entering a decimal comma such as 1,5, which is rejected to avoid treating it as 15 or 1,500.
Output guide
Rounded value is the final two-decimal result. Precision confirms the target is 2 decimals. Rounding mode identifies half up, while Decision reports whether the thousandths digit caused an increase or whether the hundredths digit was kept. Hundredths digit is the second digit after the decimal before rounding, and Thousandths digit is the deciding third digit. Truncated to hundredths shows the provisional value before the decision. The exact relation line displays the validated original beside the result. In the Rounding audit, Step names the operation, Value shows the relevant number or digit, and Meaning explains its role. These outputs are exact consequences of the rule, not predictions or recommendations.
Worked example
The startup value is 1.625. The hundredths digit is 2 and the thousandths digit is 5. Because 5 meets the half-up threshold, the calculator increases the hundredths digit from 2 to 3. Therefore, 1.625 becomes 1.63. The provisional value is 1.62, and the final result differs because the deciding digit triggers the increment.
How the rounding rule works
Nearest hundredth = keep two decimal places, then use the third decimal digit to decide whether to add one hundredth.
Digits 0 through 4 leave the provisional hundredths value unchanged. Digits 5 through 9 increase the magnitude by one hundredth. This treatment of ties is called half up; the Python Decimal documentation distinguishes half-up rounding from half-even and other modes.
Carry propagation matters. In 4.0962, the provisional value is 4.09, but the thousandths digit is 6, so the 9 in the hundredths place becomes 0 and the tenths digit increases: 4.10. In 4.9962, the carry continues through both decimal digits and produces 5.00.
Precision versus accuracy
Writing two decimal places states a level of displayed precision, but it does not automatically make a measurement more accurate. For technical reporting, decimal places should remain consistent with source-data quality and measurement uncertainty. NIST's metric publications and SI guidance discuss rounding in the broader context of reporting measured and converted quantities.