Significant figures calculator

Count the significant figures in a number and round to a chosen sig-fig count. Trailing zeros after a decimal point ARE significant; trailing zeros in a whole number are ambiguous (use scientific notation to disambiguate).

Significant figures
0
Rounded value
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Scientific form
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Decimal places
0

Rules for counting sig figs

  1. All non-zero digits ARE significant. (456 → 3 sig figs)
  2. Zeros between non-zero digits ARE significant. (1002 → 4)
  3. Leading zeros are NOT significant. (0.0045 → 2)
  4. Trailing zeros AFTER a decimal point ARE significant. (4.500 → 4)
  5. Trailing zeros in a whole number without a decimal are ambiguous. Write as scientific notation to disambiguate.