Engineering Notation Converter
Rewrite a number in engineering notation, scientific notation and SI prefix form.
What is Engineering Notation?
Engineering notation is scientific notation with the exponent restricted to a multiple of three: a mantissa between 1 and 1000, and an exponent of …, −6, −3, 0, 3, 6, …. The restriction is the whole point — every multiple of three corresponds to an SI prefix, so an engineering-notation figure can be read aloud with its unit and converted without an error in your head.
How it works
The exponent is taken from the floor of the logarithm base ten divided by three, floored again to a multiple of three, and the mantissa is the value divided by that power of ten. The same number is then printed in scientific notation (mantissa in 1–10) and as a plain decimal, and matched against the SI prefix table from yocto to yotta. Zero is its own case: no exponent and no prefix, because it has neither. Accepts negative numbers and exponent input such as 1.2e-7.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Realistic sample
Type or paste any realistic input — the tool computes the result locally and instantly.
Common mistakes
Expecting a server round-trip
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