Significant Figures Calculator
Count significant figures and round a number to a chosen number of sig figs. Supports decimal notation, comma grouping, and E notation.
Count and round significant figures
English results for significant figures calculators combine two jobs: count the sig figs in a written number and round a value to a selected precision. This calculator keeps both outputs visible.
Leading zeros do not count. Zeros between significant digits count. Written trailing decimal zeros count.
- Enter decimal numbers, comma-grouped numbers, or E notation.
- Choose how many significant figures to keep.
- Compare the rounded decimal result with scientific notation.
Trailing zero rules
| Number | Meaning |
|---|---|
| 0.00450 | 3 significant figures: 4, 5, and the final 0 |
| 1500 | At least 2 significant figures; trailing zeros may be placeholders |
| 3 significant figures stated clearly |
Frequently Asked Questions
Sources and References
- Significant Figures CalculatorCalculatorSoup
- Significant FiguresWolfram MathWorld
- NIST Technical Note 1297NIST
Calculations are based on the listed reference sources. Links open in a new tab.
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