Count how many significant figures a number has and round it to any number of significant figures you choose. Significant figures capture the precision of a measurement: they include all non-zero digits, any zeros between them, and trailing zeros after a decimal point, while leading zeros never count. Getting the count right matters in chemistry, physics and lab reports because your reported precision should not exceed the precision of your least certain measurement. This tool reads the number exactly as you wrote it, tells you the significant figure count, and can round to a target number of sig figs using proper half-up rounding with scientific notation for clarity. Type a value and it evaluates instantly in your browser, with no data ever leaving your device.
All non-zero digits count, zeros between them count, and trailing zeros after a decimal point count. Leading zeros never count as significant.
Enter a target number of significant figures and the tool rounds the value to that precision using standard rounding rules.
Trailing zeros in a number with no decimal point are ambiguous, so this counter treats them by the standard convention and reports the count it uses.
Count how many significant figures a number has and round it to any number of significant figures you choose. Significant figures capture the precision of a measurement: they include all non-zero digits, any zeros between them, and trailing zeros after a decimal point, while leading zeros never count.
Yes. Significant Figures Counter is completely free, with no sign-up and no usage limits.
Yes. Significant Figures Counter runs in any modern web browser. There is nothing to download or install.
Yes. Significant Figures Counter runs entirely on your device in your browser, so nothing you enter is uploaded to a server.