Significant Figures Calculator

Count, round, and calculate with significant figures

Significant Figures Rules

• All non-zero digits are significant. (1, 2, 3 ... 9)
• Zeros between non-zero digits are significant. (e.g. 205 has 3 sig figs)
• Leading zeros are NOT significant. (e.g. 0.0042 has 2 sig figs)
• Trailing zeros after the decimal point ARE significant. (e.g. 2.50 has 3 sig figs)
• Trailing zeros in a whole number without a decimal point are ambiguous but typically NOT significant. (e.g. 1500 has 2 sig figs)
• Exact numbers (counts, defined values) have infinite sig figs.
• Addition/Subtraction: Result has the same number of decimal places as the term with the fewest decimal places.
• Multiplication/Division: Result has the same number of sig figs as the factor with the fewest sig figs.