Significant Figures Calculator
Count significant figures, round numbers to specified sig figs, and perform calculations with sig fig rules.
For rounding operations only
Supports standard decimal and scientific notation (e.g., 1.23e-4)
Result
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Scientific Notation
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Rule Applied
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Step-by-Step Solution
Select an operation and enter values, then click "Calculate" to see the step-by-step solution.
Significant Figures Rules
- All non-zero digits are significant
- Zeros between non-zero digits are significant
- Leading zeros are NOT significant
- Trailing zeros after decimal ARE significant
- Trailing zeros without decimal may be ambiguous
Operation Rules
- Addition/Subtraction: Round to least precise decimal place
- Multiplication/Division: Round to least number of sig figs
- Mixed operations: Follow order of operations
- Constants: Treat as having infinite sig figs
Examples
- 0.00456: 3 sig figs
- 12300: 3 or 5 sig figs (ambiguous)
- 1.2300 × 10⁴: 5 sig figs
- 12.345 + 6.789: 19.134 (3 decimal places)
Significant Figures Reference
| Number | Significant Figures | Explanation |
|---|---|---|
| 1234 | 4 | All non-zero digits |
| 1002 | 4 | Zeros between non-zero digits count |
| 0.00456 | 3 | Leading zeros don't count |
| 12.300 | 5 | Trailing zeros after decimal count |
| 1.23e-4 | 3 | Scientific notation shows sig figs |
| 1500 | 2,3,4 | Ambiguous - use scientific notation |