Significant Figures Calculator
Mastering precision in scientific measurements is essential, and this Significant Figures Calculator provides everything you need. Significant figures (or sig figs) indicate the precision of a measurement. When performing calculations in physics and chemistry, you must account for sig figs to avoid implying artificial accuracy.
This interactive tool allows you to instantly count the number of significant figures in any value, round numbers to a specific number of sig figs, and correctly perform addition, subtraction, multiplication, and division while adhering to standard laboratory error propagation rules.
Rules for Significant Figures
- Non-zero digits are always significant (e.g., 245 has 3 sig figs).
- Captive zeros between non-zero digits are always significant (e.g., 205 has 3 sig figs).
- Leading zeros are never significant. They only indicate the position of the decimal point (e.g., 0.002 has 1 sig fig).
- Trailing zeros are significant only if there is a decimal point in the number (e.g., 100.0 has 4 sig figs, but 100 has 1 sig fig).
When performing arithmetic operations, addition and subtraction depend on the number of decimal places (the result cannot have more decimal places than the number with the fewest decimal places). Multiplication and division rely on the total count of significant figures (the result should have the same number of sig figs as the factor with the fewest sig figs).