Significant Figures Calculator
Round a number to a specified number of significant figures. Essential for scientific calculations and measurement reporting.
Rounded
123,500.0000000000
Significant Figures
Rules for Counting Significant Figures
1. All nonzero digits are significant (123 has 3 sig figs) 2. Zeros between nonzero digits are significant (102 has 3) 3. Leading zeros are NOT significant (0.0045 has 2) 4. Trailing zeros after a decimal point ARE significant (2.50 has 3) 5. Trailing zeros without a decimal point are ambiguous (1500 could be 2, 3, or 4)
Rounding to n Significant Figures
1. Find the first significant digit 2. Count n digits from there 3. Round at that position
Example Calculation
Round 123456.789 to 4 significant figures.
- 01The first significant digit is 1
- 02Count 4 digits: 1, 2, 3, 4
- 03The next digit (5) rounds up
- 04Result: 123500
Frequently Asked Questions
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