Significant figures counter
Type the number exactly as written in the question or lab report, zeros and decimal point included, because the way it is written changes the count.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter number as written.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Rules: every non-zero digit counts, zeros between significant digits count, leading zeros never count, and trailing zeros count only when a decimal point is written.
Example
Inputs: Number as written = 0.004500. Result: Significant figures: 4; Certainty: Unambiguous.
0.004500
4500
Limits and caveats
- In a whole number like 1200 it is unknown whether the zeros were measured, so the lowest count is shown with the range.
- Exact numbers, by definition or by counting (12 eggs), have unlimited significant figures.
Questions about this tool
How many significant figures are in 0.004500?
Four: 4, 5 and the two final zeros. Trailing zeros after a decimal point count, leading zeros do not.
Are the zeros in 1200 significant?
It is ambiguous. Write 1200. with a point, or 1.200 × 10³, if all four digits were measured.
Does the exponent change the count?
No. Only the coefficient matters, so 6.020E23 has 4 significant figures.