# exa- [EKS uh] +

#### (Greek: from hexa-, "six"; a decimal prefix used in the international metric system for measurements)

This is a prefix that is used in the metric [decimal] system as one-quintillion [U.S.] or trillionfold [U.K.], 10^{18} [1 000 000 000 000 000 000]. The metric symbol for **exa**- is **E**.

exabit

A unit of information equal to 1000 petabits or 10

^{18}bits.A bit is a unit of measurement of information (from Binary + digIT); the amount of information in a system having two equiprobable states: "There are eight bits in a byte".

exabyte

1. A unit of information equal to 1 000 petabytes or 10

2. A unit of information equal to 1 024 pebibytes or 2

^{18}bytes.2. A unit of information equal to 1 024 pebibytes or 2

^{60}bytes.
exagram (Eg)

A unit of mass equal to 1,000,000,000,000,000,000 grams.

exajoule

A measure of energy, symbol EJ; 10

^{18}J, equivalent to 10^{15}Btu.
exasecond (Es)

The age of the universe is estimated to be 0.4 exasecond (12 billion years).

Related **"metric"** families:
**yotta**;
**zetta**;
**peta**;
**tera**;
**giga**;
**mega**;
**kilo**;
**hecto**;
**deka**;
**deci**;
**centi**;
**milli**;
**micro**;
**nano**;
**pico**;
**femto**;
**atto**;
**zepto**;
**yocto**.

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Showing 1 page of 5 main-word entries or main-word-entry groups.