What is the standard measurement system used by scientists around the world?

Measurements in science are made in Système International (SI) units. The use of SI units was agreed upon by an international association of scientists in 1960.

The SI system is a base 10 system. This means that units in the SI system vary by multiples of ten. Base units are established and prefixes are used to indicate smaller and larger units. 

Base Units:

length: meter (m)

volume: cubic meter (`~m^3` )

mass: kilogram (kg)

temperature: Kelvin (K)

energy: Joule (J)

Prefixes:

mega (M) - multiply base unit by `~10^6`

kilo (k) - multiply base unit by `~10^3`

deci (d) - multiply base unit by `~10^-^1`

centi (c) - multiply base unit by `~10^-^2`

milli (m) - multiply base unit by `~10^-^3`

micro (`mu` ) - multiply base unit by `~10^-^6` ` `

nano (n) - multiply base unit by `~10^-^9`

pico (p) - multiply base unit by `~10^-^12`