Rounding Calculator
Round numbers to any decimal place or significant figure with multiple rounding methods.
Result
Fill in the fields above, then press Calculate.
A rounding calculator rounds numbers to a specified place value or significant figures, showing floor and ceiling values alongside the result.
Examples
Decimal places
3.14159 rounded to hundredths = 3.14 (9 < 5 at thousandths would give 3.142, but hundredths looks at 1)
Whole numbers
3,456 rounded to hundreds = 3,500 (56 rounds up)
Significant figures
0.004567 to 2 sig figs = 0.0046 (first two non-zero digits: 4 and 5, then round)
Frequently Asked Questions
What are significant figures?
Significant figures are all digits that carry meaning, starting from the first non-zero digit. Leading zeros are not significant. For example, 0.00450 has 3 significant figures.
What happens when the digit is exactly 5?
Standard convention rounds up when the digit is 5. Some scientific contexts use "round half to even" (banker's rounding) to reduce bias.
Why does rounding matter?
Rounding communicates precision. Reporting a measurement as 3.14 vs 3.14159 indicates different levels of certainty about the value.
Result
Your result appears here and follows you as you scroll.
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Quick Tips
- •Double-check your inputs — small errors lead to incorrect results.
- •Use significant figures mode when working with scientific measurements.
- •Be aware that some scientific contexts use bankers rounding (round half to even) instead of standard rounding.