Sig Fig Calculator

Count and round significant figures from the typed number, including decimal zeros, exact numbers, and scientific notation.

Trailing zeros after a decimal are counted. Whole-number trailing zeros need context.

Input kind
Action

Significant figures

Enter a number

Lexical parser preserves decimal points, trailing zeros, and exponent notation.

Scientific notation
Not calculated
Rounded value
Only shown in round mode
Rule trace
DigitCountsReason
Export

significant digits are counted from the first nonzero digit, with decimal trailing zeros preserved How?

How this is calculated

The tool parses the typed string instead of converting it to a JavaScript number. Nonzero digits count, leading zeros do not, zeros between nonzero digits count, and trailing zeros after a decimal point count. Whole-number trailing zeros without a decimal point are ambiguous, so the selected convention is shown.

Exact-number mode reports unlimited significant figures. Round mode keeps the full typed precision until the final display and uses tie-to-even rounding unless half-up is selected.

Formula: significant digits are counted from the first nonzero digit, with decimal trailing zeros preserved

Sources

  1. OpenStax Chemistry 2e, Measurement Uncertainty, Accuracy, and Precision. OpenStax. Retrieved .
  2. OpenStax Chemistry 2e, Mathematical Treatment of Measurement Results. OpenStax. Retrieved .

Method last reviewed