The metric system originated in France in 1799 although decimal units had been used in many other countries and cultures previously. Although there have been many different measurements and the definitions of the units have been revised, the official system of measurements of most countries is the modern form of the metric system which is known as the “International System of Units”. The U.S.A, Liberia, and Burma use the Imperial System.
Length
1 kilometer 0.62137 mile 1 meter 3.2808 foot 1 centimeter 0.3937 inche 1 mile 1.6093 kilometer 1 foot 0.3048 meter 1 inch 2.54 centimeters
Weight
1 kilogram 2.2046 lbs 1 gram 0.0353 ounce 1 short ton 907.1847 kilogram 1 pound 0.4536 kilogram 1 ounce 28.3495 grams
Volume
1 hectoliter 100 liters 1 liter 100 centileter 1 gallon (U.S.) 3.7853 liters 1 cubic inch 16.3871 cubic cm 0.1 cubic meter 26.4172 gallons 1 cubic decimeter 1.0567 quarts
Area
1 square kilometer 1 million sq.meters 0.3861 sq.miles 1 hectare 10.000 sq. meters 2.471 acres 1 square meter 10.7639 sq.feet 1550.003 sq.inches 1 square mile 640 acres 258.9988 hectares 1 square foot 144 square inches 258.9988 hectares
Length
Symbol If you have Multiply by To get Symbol mm millimeters 0.03937 inches in cm centimeters 0.3937 inches in m meters 3.3 feet ft m meters 1.1 yards yd km kilometers 0.6 miles mi in inches 2.54 centimeters cm ft feet 30.48 centimeters cm yd yard 0.9 meters m mi miles 1.6 kilometers km
Area
Symbol If you have Multiply by To get Symbol cm2 square centimeters 0.16 square inches in2 m2 square meters 1.2 square yards yd2 km2 square kilometers 0.4 square miles mi2 ha2 hectares (10,000 m2 ) 2.5 acres ft2 square feet 0.09 square meters m2 yd2 square yard 0.8 square meters m2 mi2 square miles 2.6 sq. kilomters km2
Weight
Symbol If you have Multiply by To get Symbol * grams 0.035 ounce oz kg kilograms 2.2046 pounds lb t tonnes (1,000 kq) 1.1 short tons lb pounds 0.45 kilograms kg
Volume
Symbol If you have Multiply by To get Symbol ml milliliters 0.03 fluid ounces fl oz l liters 2.1 pints pt l liters 1.06 quarts qt l liters 0.26 gallons gal m3 cubic meters 35.314 cubic feet ft m3 cubic meters 1.3 cubic yards yd3 tsp teaspoons 5 millimeters ml tbsp tablespoons 15 millimeters ml fl oz fluid ounces 30 millimeters ml c cups 0.24 liters l