Metric Basics

The three basic metric units are the meter (length), the gram (weight), and the liter (volume). The key to metric prefixes are:

  • 1000 = kilo
  • 100 = hecto
  • 10 = deca
  • 0.1 = deci
  • 0.01 = centi
  • 0.001 milli
COMMON MEASUREMENTS
Length
1 kilometer = 0.62137 mi
1 meter = 3.2808 ft
1 centimeter = 0.3937 in
1 mile = 1.6093 km
1 foot = 0.3048 m
1 inch = 2.54 cm
Weight
1 kilogram = 2.2046 lbs
1 gram = 0.0353 oz
1 short ton = 907.1847 kilos
1 pound = 0.4536 kilos
1 ounce = 28.3495 g
Volume
1 hectoliter = 100 l = 0.1 m³ = 26.4172 gal
1 liter = 100 cl = 1 dm³ = 1.0567 qt
1 gallon (U.S.) = 3.7853 l
1 cubic inch = 16.3871 cm³
Area
1 hectare = 10,000 m² = 2.471 acres
1 square meter = 10.7639 ft² = 1550.003 in²
1 square mile = 640 acres = 258.9988 ha²
1 square foot = 144 in² = 929.0304 cm²