Significant Figures Calculator
Free online significant figures calculator. Count and round to significant figures with rules for zeros and decimals.
About the Significant Figures Calculator
Count significant figures in a valid decimal or e-notation number and view the explanation and scientific notation. Decimal trailing zeros are counted; trailing zeros in whole numbers without a decimal are treated as insignificant. This tool does not provide a separate rounding control.
Features
- Significant-figure count
- Decimal and e-notation input
- Scientific notation output
How to use this tool
The Significant Figures Calculator works right in your browser — no signup, no installation. Follow these steps:
- Enter a number with any decimal places and zeros.
- The calculator instantly shows the sig fig count and highlights significant digits.
- Optionally set a target sig fig count to round the number.
- View the result and the rule explanation.
Frequently asked questions
How does this tool work?
Count significant figures in a valid decimal or e-notation number and view the explanation and scientific notation. Decimal trailing zeros are counted; trailing zeros in whole numbers without a decimal are treated as insignificant. This tool does not provide a separate rounding control.
Using the results
Use the Significant Figures Calculator to calculate from the values you enter. Check the displayed units, rounding and supported inputs when interpreting the result.