Significant Figures Counter

Count the significant figures in any number, including decimals, trailing zeros and values written in scientific notation.

Significant figures counter

Treat trailing zeros in whole numbers as significant

Significant figures: —

Significant digits: —

Leading zeros are never significant, and trailing zeros count only when the number has a decimal point.

Type or paste the number you want to check.
Optionally tick the box to count trailing zeros in whole numbers as significant.
Read the number of significant figures and the significant digits found.

Common questions about the free online significant figures counter.

Significant figures are the digits in a number that carry meaning for its precision, ignoring the zeros used only as place holders.

Enter the number and the count appears instantly. The tool also lists the significant digits it found in the value.

No. Zeros before the first non-zero digit only fix the decimal place, so a value like 0.00345 has three significant figures.

They are significant when the number contains a decimal point. In a whole number such as 1500 they usually are not.

Yes. Tick the checkbox and a whole number such as 1500 is then counted as having four significant figures.

Yes. Values such as 1.20e3 are accepted and the count is taken from the coefficient, which gives three significant figures.

Zero is a special case and is counted as having one significant figure, because no digit in it carries precision.

Significant figures show how precise a measurement is, and they control how rounded the final answer should be reported.

No. The counting runs entirely in your browser, so the numbers you enter never leave your device.

Last updated: October 10, 2026