Includes your current inputs. Anyone with the link can read them.
Count significant figures and format values in scientific or engineering notation with round-half-to-even rounding.
Enable JavaScript to use the interactive calculator. Formulas and examples are available below.
Leading zeros locate the decimal point; zeros between significant digits count. Decimal trailing zeros can communicate measured precision. The value 0.00450 has three significant figures and can be written as 4.50 × 10⁻³.
At three significant figures, 12.345 becomes 12.3. In an exact tie, round-half-to-even chooses an even retained digit: 1.245 becomes 1.24 and 1.255 becomes 1.26 at three significant figures.
Without a decimal point or uncertainty statement, trailing zeros in an integer may not specify precision. Write 1.2 × 10³ for two significant figures or 1.200 × 10³ for four.
Engineering notation uses exponents divisible by three. For example, 0.00045 is 4.5 × 10⁻⁴ in scientific notation and 450 × 10⁻⁶ in engineering notation.
Reference text updated . For research and teaching reference. Verify results against your course or laboratory protocol.