Scientific notation converter

Write any number as a × 10ⁿ, in E notation or in engineering form, and back.

Formula Maths

Scientific notation

E notation: 1.23e-4
Engineering notation: 123 × 10⁻⁶
Decimal: 0.000123
Order of magnitude: -4

How it works

Scientific notation writes a number as a mantissa between 1 and 10 multiplied by a power of ten. The power counts how many places the decimal point moves.

E notation is the same thing for keyboards: 1.23e-4 means 1.23 × 10⁻⁴. Engineering notation keeps the power a multiple of 3, matching prefixes such as kilo, mega and micro.

The conversion is exact; digits are only dropped when you ask for fewer significant figures.

Formula

x = a × 10ⁿ, 1 ≤ |a| < 10
n = floor(log₁₀ |x|)
engineering: n is a multiple of 3

Worked example

0.000123 = 1.23 × 10⁻⁴, written 1.23e-4 in E notation and 123 × 10⁻⁶ in engineering notation. 6.02e23 is 602,000,000,000,000,000,000,000.

Questions people ask

What is standard form?

In the UK, standard form is another name for scientific notation: a number from 1 to under 10 times a power of ten.

How do I write a small number in scientific notation?

Move the decimal point right until one non-zero digit is in front of it; the number of moves is the negative power. 0.0045 = 4.5 × 10⁻³.

What does the E mean on a calculator?

E stands for “times ten to the power of”. 3.2E5 is 3.2 × 10⁵ = 320,000.