# Metric System Prefixes

## This article lists the most common metric system prefixes and what number they stand for.

Most of the world uses the metric system as the standard set of units, as does the scientific community worldwide. In the metric system, each type of measurement has a base unit, such as meter for distance, liter for volume, etc. Prefixes are then added to the base unit to specify how much of that unit is present. The value of the base unit is multiplied by the value signified by the prefix to obtain the value of the full measurement. The most common prefixes are:

tera: tera multipies a metric unit by 10^12, or 1000000000000

giga: giga multiplies a metric unit by 10^9, or 1000000000 (one billion)

mega: mega multiplies a metric unit by 10^6 or 1000000 (one million)

kilo: kilo multiplies a metric unit by 10^3 or 1000 (one thousand)

hecto: hecto multiplies a metric unit by 10^2 or 100 (one hundred)

deka: deka multiplies a metric unit by 10^1 or 10 (ten)

deci: deci multiplies a metric unit by 10^-1 or 1/10 (one tenth)

centi: centi multiplies a metric unit by 10^-2 or 1/100 (one hundredth)

milli: milli multiplies a metric unit by 10^-3 or 1/1000 (one thousandth)

micro: micro multiplies a metric unit by 10^-6 or 1/1000000 (one millionth)

nano: nano multiplies a metric unit by 10^-9 or 1/1000000000 (one billionth)

pico: pico multiplies a metric unit by 10^-12 or 1/1000000000000

femto: femto multiplies a metric unit by 10^-15 or 1/1000000000000000

The origins of these prefixes are quite interesting because each section of sizes has been adopted from a different language. The prefixes for very large multipliers - tera, giga, and mega - come from Greek. The small magnitude multipliers - kilo, hecto, deka, deci, and centi - all come from French. We took milli from Latin, surprisingly the only prefix taken from this once widespread language. The next range of fractional multipliers - micro and nano - also come from Greek. The large fractional multipliers were defined later than the others, and pulled from other languages. We took pico from Spanish and femto from Danish.

So not only are these metric prefixes used worldwide, but their origins are international, too.