Scientific notation converter

Scientific notation writes very large or very small numbers compactly as a coefficient multiplied by a power of ten, such as 6.022 × 10^23 for Avogadro's number or 1.6 × 10^-19 for the charge of an electron. This converter switches between standard decimal form, scientific notation, E notation used by calculators and programming languages, and engineering notation.

How to use it

1. Enter a number in any form, such as 0.000045, 4.5e-5 or 4.5 × 10^-5.
2. Read the equivalent forms.
3. Copy the representation you need.

The notations

• Scientific: one non-zero digit before the decimal point. 299,792,458 = 2.99792458 × 10^8.
• E notation: the same, written 2.99792458e8. Used by spreadsheets and most programming languages.
• Engineering: the exponent is a multiple of 3, matching SI prefixes. 0.000045 = 45 × 10^-6, which is 45 micro.

Converting by hand

Move the decimal point until one non-zero digit remains in front of it, and count the moves. Moving left gives a positive exponent; moving right gives a negative exponent. 0.00078 needs 4 moves to the right, so it is 7.8 × 10^-4.

Engineering notation and SI prefixes

• 10^3 kilo (k), 10^6 mega (M), 10^9 giga (G), 10^12 tera (T)
• 10^-3 milli (m), 10^-6 micro (µ), 10^-9 nano (n), 10^-12 pico (p)

A resistor of 4.7 × 10^3 ohms is 4.7 kΩ; a capacitor of 100 × 10^-9 F is 100 nF.

Significant figures

Scientific notation shows precision explicitly: 1.20 × 10^3 has three significant figures, while 1.2 × 10^3 has two.