Scientific notation converter with significant figures
Convert a number to scientific notation, get engineering notation with exponents in multiples of three, and count its significant figures.
Runs entirely in your browser — nothing is uploaded.
Plain decimal or existing scientific notation, e.g. 1234.5 or 1.2345e3
Significant figures are counted from the digits as you typed them. Trailing zeros in a whole number with no decimal point are treated as not significant, following the usual convention — write 1.200 × 10³ if they are.
How to use
- Enter a number. Plain decimal or existing scientific notation such as 1.2345e3.
- Read the three forms. Scientific, engineering, and plain decimal.
- Check the significant figures. Counted from the digits exactly as you wrote them.
Questions
What is scientific notation?
A number written as a coefficient between 1 and 10 multiplied by a power of ten. 1234.5 becomes 1.2345 × 10³, and 0.00042 becomes 4.2 × 10⁻⁴. It keeps very large and very small numbers readable.
How is engineering notation different?
The exponent is always a multiple of three, so it lines up with SI prefixes — kilo, mega, milli, micro. 12345 is 1.2345 × 10⁴ in scientific but 12.345 × 10³ in engineering, which reads directly as 12.345 kilo-something.
Which zeros are significant?
Leading zeros never are. Zeros between digits always are. Trailing zeros after a decimal point are. Trailing zeros in a whole number with no decimal point are ambiguous — this tool follows the usual convention of not counting them, so 1200 reads as 2 significant figures. Write 1.200 × 10³ if you mean four.
Why does the count depend on how I type it?
Because significant figures describe measurement precision, which lives in the notation rather than the value. 1.0 and 1.00 are numerically equal but claim different precision, so the count is taken from your input rather than the parsed number.