How to use Rounding and Significant Figures Calculator
- Enter the decimal value.
- Choose decimal places or significant figures and set the precision.
- Choose the rounding rule and inspect the result.
Example: Rounding and Significant Figures Calculator
Round a decimal to two places.
You add
Value: 1234.567. Mode: decimal places. Places: 2. Rule: half-up.
You get
The rounded result is 1234.57.
Supported inputs and limits
Decimal places -6 through 12 or 1–15 significant figures, with up to 1,000 input digits, an exponent within ±1,000 and a 5,000-character output cap. Rules cover negatives and halfway cases. Measurement uncertainty is not inferred from the input.
Where your input is processed
This tool processes your input in this browser. Your text and files are not uploaded to UseFreeTools. Check this tool's limits for anything it may save on your device.
Figures and places describe different precision
Decimal places count positions after the decimal mark. Significant figures count from the first nonzero digit. Choose the one that matches how you need to report the number.
Questions about Rounding and Significant Figures Calculator
How do half-up and half-even differ?
At an exact halfway point, half-up rounds away from zero. Half-even chooses the neighbor with an even retained digit.
What do negative decimal places do?
They round to tens, hundreds and larger powers of ten rather than digits after the decimal mark.
Is truncation the same as floor?
No. Truncation moves toward zero; floor moves toward negative infinity. They differ for negative values.