Significant Figures Calculator

1) Non-zero digits are always significant. 2) Zeros between non-zero digits are significant (1205 has 4 sig figs). 3) Leading zeros are never significant (0.0042 has 2 sig figs). 4) Trailing zeros after a decimal point are significant (3.50 has 3 sig figs). 5) Trailing zeros in a whole number without a decimal are ambiguous (1200 could be 2, 3, or 4 sig figs).

For addition/subtraction: the result has the same number of decimal places as the measurement with the fewest decimal places. Example: 12.52 + 349.0 + 8.24 = 369.76 → rounded to 369.8 (because 349.0 has only 1 decimal place).

For multiplication/division: the result has the same number of significant figures as the measurement with the fewest sig figs. Example: 4.56 × 1.4 = 6.384 → rounded to 6.4 (because 1.4 has only 2 sig figs).