What this tool answers
This tool examines how a number is written. It counts significant figures rather than changing the value to a chosen precision. Keep the original zeros in the input because numeric conversion can discard their meaning.
Formula
Ignore leading zeros; count interior zeros and trailing zeros following a decimal point.
Worked example: A measured decimal with four significant figures
The written number 0.007020 has four significant figures: 7, 0, 2 and the final 0. The zeros before 7 locate the decimal position; they do not add precision.
Load these worked-example inputs
Limitations
A bare whole number ending in zeros can be ambiguous. Use scientific notation or an explicit decimal convention when the intended measurement precision must be clear.
Frequently asked questions
Why must I retain the final zero in 0.007020?
That trailing decimal zero is part of the written precision and contributes one significant figure.
Does counting significant figures round my input?
No. Counting reports the precision implied by the notation without choosing a new rounded value.
How can I remove ambiguity from whole-number zeros?
Use scientific notation that explicitly states the intended significant digits.