Engineering notation is the form scientists and engineers reach for when they want numbers that map cleanly onto SI unit prefixes. This converter rewrites any value so its exponent is a multiple of three and tells you the matching prefix.
How it works
Ordinary scientific notation writes a number as a mantissa between 1 and 10 times a power of ten with any integer exponent. Engineering notation keeps the same idea but constrains the exponent to be a multiple of three. As a consequence, the mantissa can range anywhere from 1 up to just below 1000.
To convert, the tool first computes the standard base-10 exponent as the floor of the logarithm of the absolute value. It then rounds that exponent down to the nearest lower multiple of three to get the engineering exponent. Finally it divides the original number by ten raised to that engineering exponent to obtain the mantissa.
Example
Take 47000. Its base-10 exponent is 4 (since it is between 10⁴ and 10⁵). Rounding 4 down to the nearest multiple of three gives 3. Dividing 47000 by 10³ gives a mantissa of 47, so the engineering form is 47 × 10³. The exponent 3 corresponds to the SI prefix kilo, so 47000 hertz is naturally read as 47 kHz.
Tips and notes
Engineering notation is why component values are quoted as 4.7 kΩ rather than 4700 Ω, or a capacitor as 2.2 µF rather than 0.0000022 F. The converter accepts scientific input like 1.2e9 directly and covers the full SI prefix ladder from yocto to yotta. All processing happens locally in your browser.