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Calculation Machine

Significant Figures Calculator

Count sig figs and round to any precision.

Reviewed by the Calculation Machine team · How we check our maths

Your values

ⓘ Live results

Results
Significant figures
5
Rounded to 3 sig figs
0.0043
In scientific notation
4.30e-3
Decimal places in original
7

Working

  1. 1Leading zeros never count; trailing zeros count only after a decimal point.

Quick answer

Significant figures are the digits that carry meaning: all non-zero digits, zeros between them, and trailing zeros after a decimal point.

Worked example

Worked example

Using the values the calculator loads with.

Inputs

  • Number0.0043020
  • Round to how many sig figs3

Result

  • Significant figures5
  • Rounded to 3 sig figs0.0043
  • In scientific notation4.30e-3
  • Decimal places in original7

How to use the Significant Figures Calculator

  1. 1Type the number exactly as written, keeping trailing zeros.
  2. 2Choose how many sig figs to round to.
  3. 3Read the count and rounded value.

Frequently asked questions

Do trailing zeros count?

After a decimal point yes — 2.500 has four sig figs. In a whole number like 2500 they are ambiguous without scientific notation.

Which rule applies to multiplication?

The answer carries the same number of sig figs as the least precise factor. For addition, match decimal places instead.

About this calculator