Engineering Notation Converter
Enter any decimal number and read it back in engineering notation — a coefficient between 1 and 1000 times a power of ten that is always a multiple of three, lined up with SI prefixes.
Exponent in steps of three
The exponent is locked to multiples of three, so the result maps straight onto SI prefixes like kilo (10³), mega (10⁶), and milli (10⁻³).
Wider coefficient range
Unlike scientific notation, the coefficient can run from 1 up to 1000 — so 47000 becomes 47 × 10³, not 4.7 × 10⁴.
What is engineering notation?
Scientific notation aligned to SI prefixes
Engineering notation is a variant of scientific notation in which the exponent is always a multiple of three and the coefficient sits between 1 and 1000. That restriction lets every result map cleanly onto an SI prefix — 10³ is kilo, 10⁻³ is milli, 10⁶ is mega — which is exactly how engineers quote resistances, capacitances, frequencies, and power.
Enter a number to see its engineering-notation coefficient, exponent, and SI prefix, ready for datasheets and circuit work.
Round the base-10 exponent down to the nearest multiple of three, then divide the number by that power of ten to get the coefficient.
value = coefficient × 10^exponent (exponent a multiple of 3)Take 47000. The base-10 logarithm is about 4.67; rounding down to the nearest multiple of three gives an exponent of 3, so you divide by 10³ = 1000 to get a coefficient of 47. The number is therefore 47 × 10³, which an engineer reads as 47 k — for example 47 kΩ. A small value like 0.0042 becomes 4.2 × 10⁻³, or 4.2 m (milli).
The coefficient and exponent together tell you the magnitude in the units engineers actually speak. Because the exponent moves in steps of three, the SI prefix follows directly: 10³ is kilo (k), 10⁶ is mega (M), 10⁹ is giga (G), while 10⁻³ is milli (m), 10⁻⁶ is micro (µ), and 10⁻⁹ is nano (n). So 2.2 × 10⁻⁶ F is read as 2.2 µF, and 1.5 × 10⁹ Hz is 1.5 GHz. The coefficient can be anywhere from 1 up to just under 1000, which is the main difference from scientific notation — there 47000 would be 4.7 × 10⁴, but engineering notation keeps the exponent on a prefix boundary so the figure stays human-readable. When you compare two values, line up their prefixes first, then their coefficients.
Engineering notation is exact, but a couple of conventions matter.
Prefix range and rounding
SI prefixes are defined for exponents from −24 (yocto) to +24 (yotta); a value outside that range still gets a correct exponent but no standard prefix symbol. The coefficient is rounded to ten decimal places to absorb floating-point noise, which can trim trailing digits of numbers that already carry many significant figures. Engineering notation is a presentation format — it does not change the value, only how it is written.