Math · Measurement

Sig Fig Calculator

Count and round to significant figures with scientific notation — every digit color-coded as significant or not.

Rounded result
—
Sig fig rules: all non-zero digits are significant; zeros between non-zero digits are significant; leading zeros are not; trailing zeros after the decimal point are significant.
Example: 0.0045600 has 5 significant figures.

Digit highlighting

Significant digits glow cyan, insignificant zeros are marked yellow.

Scientific notation

Results shown in both plain and scientific notation.

Rule explanation

Step-by-step count with the reason each digit counts.

Instant results

Every keystroke recalculates the count and rounding.

More Measurement Tools

Explore measurement and conversion calculators.