Math · Measurement

Sig Fig Calculator

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

Number

Round to sig figs

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.

Rounding Calculator Scientific Notation Unit Converter