Significant Figures Calculator
Count sig figs and round correctly.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Significant figures
- 4
- Rounded to 2 sig figs
- 0.0045
- Scientific notation
- 4.520e-3
- Decimal places
- 6
- Ambiguous trailing zeros?
- No
Working
- 10.004520 has 4 significant figures.
Quick answer
Significant figures are all certain digits plus one estimated digit; leading zeros never count, trailing zeros count only after a decimal point.
How to use the Significant Figures Calculator
- 1Type the number exactly as written, keeping trailing zeros.
- 2Set how many significant figures you need.
- 3Read the count and rounded value.
Frequently asked questions
Do leading zeros count?
No. In 0.00452 only 4, 5 and 2 are significant — the zeros just place the decimal point.
How do sig figs work in multiplication?
The result carries as many significant figures as the least precise input.