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Metric Weights and Measures

  

The metric system is based on 10s. For example, 10 millimeters = 1 centimeter, 10 centimeters = 1 decimeter, and 10 decimeters = a meter (39.37 inches).

Units smaller than a meter have Latin prefixes:
Prefix Meaning Number in 1 meter
deci-1010 decimeters
centi-100100 centimeters
milli-1,0001,000 millimeters
micro-1,000,0001,000,000 micrometers
nano-1,000,000,0001,000,000,000 nanometers
pico-1,000,000,000,0001,000,000,000,000 picometers
Units larger than a meter have Greek prefixes:
Prefix Meaning Relative Measurements
deka-10dekameter = 10 meters
hecto-100hectometer = 100 meters
kilo-1,000kilometer is 1,000 meters
mega-1,000,000megabyte = one million bytes
giga-1,000,000,000gigabyte = one billion bytes
tera-1,000,000,000,000terabyte = one trillion bytes
peta-1,000,000,000,000,000petabyte = one quadrillion bytes

The Bureau International des Poids et Measures (BIPM) brochure on the International System of Units (SI) contains more details about prefixes.

Metric System Examples

Rules of Thumb

  • A meter is a little more than a yard.
  • A kilometer is less than a mile.
  • A liter is a little more than a quart.
Length
Unit Value
kilometer (km) 1,000 meters
hectometer (hm) 100 meters
dekameter (dam) 10 meters
meter (m) 1 meter
decimeter (dm) 0.1 meter
centimeter (cm) 0.01 meter
millimeter (mm) 0.001 meter
Capacity
Unit Value
kiloliter (kl) 1,000 liters
hectoliter (hl) 100 liters
dekaliter (dal) 10 liters
liter (l or L) 1 liter
deciliter (dl) 0.1 liter
centiliter (cl) 0.01 liter
milliliter (ml) 0.001 liter

Metric Conversions

For accurate conversions, see the National Institute of Standards and Technology (NIST) Special Publiciations: Complete NIST Special Publications 330 and 811:
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