Significant Figures Calculator

Count the significant figures in a number and round to any number of sig figs, with the rule shown.

How to count significant figures

  1. Enter your number exactly as written, including trailing zeros.
  2. The calculator applies the sig-fig rules to count them.
  3. Optionally round to a chosen number of significant figures.

Frequently asked questions

What are the rules for significant figures?

All non-zero digits are significant. Zeros between non-zero digits are significant. Leading zeros are never significant. Trailing zeros are significant only when there is a decimal point.

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