# What metric units do scientist use?

Mass: kilograms (kg) instead of ounces/pounds. The gram (g, 1 kg = 1000 g) and the miligram (mg, 1 g = 1000 mg) are also very used.

Length: metres (m) instead of miles/yards/feet/inches ... The kilometre (km, 1 km = 1000 m), the centimetre (cm, 1 m = 100 cm) and the milimetre (mm, 1 m = 1000 mm) are also very used.

Area: square metres (m2) are mainly used (also square centimetres (cm2)) instead of square yards / acres / ...

Volume: litres (L) are very common instead of pints/ounces/... In the case of water, 1 L = 1 dm3 (1 m = 10 dm). In the same way, centilitres (cL, 1 L = 100 cL) and mililitres (mL, 1 L = 1000 mL) are also common.

Temperature: No Fahrenheit degrees! Kelvin (K) and Celsius degrees (ºC) are used. 0 K is the point at which all molecular and atomic motion stops: that's -273 ºC (sorry if you're not familiar with scientific definitions). 0 ºC equals 32 ºF and is the point at which pure water freezes, and 100 ºC equals 212 ºF and is the point at which water boils. You can easily convert temperatures like this:

K = ºC + 273

ºF = ºC * 1.8 + 32

From mass (kg), length (m), time (s) and temperature (K), you can derive any other familiar unit. (You'll need three other basic units to derive any unit you want: ampere (A), mole (mol) and candela (CD))

So, for example, you don't measure speed in miles per hour, but in metres per second (m/s) or kilometres per hour (km/h).

Hope you understand it!