United States customary units

U.S. customary units are the main defacto official system of units of measurement used to measure things in the United States and U.S. territories (except in Puerto Rico and Guam, where the metric system is also officially used and is dominant).  The system of Imperial units, on which the U.S. customary units are based, is very similar but there are some differences.

Length or distance units include the inch, foot, yard and mile.

Land units include square miles (2589998.47032 square meter) and acres (4046.8726 square meter).

Common volume units are the teaspoon, tablespoon (3 teaspoons), fluid ounce (two tablespoons), cup (8 ounces), pint (2 cups, or 16 fluid ounces), quart (2 pints, or 32 fluid ounces), US gallon (16 cups, 128 fluid ounces, or 3.8 liters).

A barrel is the unit to measure oil.

Temperature is measured in degrees Fahrenheit (°F). Here is a formula to convert from °C to °F: 

Units of weight and mass include the pound (453.6 grams), which contains 16 ounces. This should not be confused with the British pound which is a type of money. The different uses of the word pound can cause confusion. Different sizes of ounce are also in use.

Some people have been trying to replace these units with the metric system since the 1820s. Much infrastructure in the United States and British Empire was built in past centuries using the old measures. During the 20th century some sectors such as science, medicine and the military of the United States converted to metric but the majority Americans still primarily use the old units for daily purposes and most government documents list measurements in the US customary system only. On the other hand, world trade is conducted using the metric system and except for the US and Liberia, the world uses the metric system for almost all purposes.

 Length 
 unit   equal to  Metric 1 thou or mil   inch  0.0254 mm1 point (p)  0.4 mm1 pica (P)   12 points 4.2 mm1 inch (in)  6 picas  2.54 cm1 foot (ft)  12 inches 30.48 cm1 yard (yd)  3 feet 0.9144 m1 mile (mi)  1760 yards   1.609344 km

 Area 
 Unit  Equal to  Metric1 square (survey) foot (sq ft or ft2)   0.0929 m21 square chain (sq ch or ch2)  4356 sq ft  404.7 m21 acre  10 sq ch  4 047 m21 section  640 acres  2.6 km21 (survey) township (twp)  36 sections  93.2 km2

 Volume 
+ Capacity Volume Unit  Equal to  Metric1 cubic inch (cu in) or (in3)   16 mL1 cubic foot (cu ft) or (ft3)  1728 cu in  28 L1 cubic yard (cu yd) or (yd3)  27 cu ft  766.55 L1 acre-foot (acre ft)  1613.333 cu yd  1,233,000 L

+ Liquid volume Unit  Equal to  Metric1 minim (min)  1 drop   0.1 mL1 US fluid dram (fl dr)  60 min  3.7 mL1 teaspoon (tsp)  80 min  4.92892 mL1 tablespoon (Tbsp)  3 tsp  14.7868 mL1 US fluid ounce (fl oz)  2 Tbsp  29.5735 mL1 US shot (jig)  3 Tbsp  44 mL1 US gill (gi)  4 fl oz  118.294 mL1 US cup (cp)  2 gi  240 mL1 (liquid) US pint (pt)  2 cp  473.176 mL1 (liquid) US quart (qt)  2 pt  0.946353 L1 (liquid) US gallon (gal)  4 qt  3.78541 L1 (liquid) barrel (bbl)  31.5 gal  119.2405 L1 oil barrel (bbl)  42 gal  158.987 L1 hogshead  63 gal  238.481 L

+ Dry Volume Unit  Equal to  Metric1 (dry) pint (pt)   0.6 L1 (dry) quart (qt)  2 pt  1.1 L1 (dry) gallon (gal)  4 qt  4.4 L1 peck (pk)  2 gal  8 L1 bushel (bu)  4 pk  35 L1 (dry) barrel (bbl)  3.281 bu  110 L

 Mass and weight 
+ Avoirdupois Unit  Equal to  Metric 1 grain (gr)   65 mg1 dram (dr)  27 11⁄32 gr  1.8 g1 ounce (oz)  16 dr  28.3495 g1 pound (lb)  16 oz  453.592 g1 US hundredweight (cwt)  100 lb  45.3592 kg1 long hundredweight  112 lb  50.802345 kg1 short ton  20 US cwt   907.185 kg1 long ton  20 long cwt   1,016.047 kg
+ Troy Unit  Equal to  Metric 1 grain (gr)   65 mg1 pennyweight (dwt)  24 gr  1.55517 g1 troy ounce (oz t)  20 dwt  31.1035 g1 troy pound (lb t)  12 oz t  373.242 g

Related pages
Units of measurement

 Notes 

References

Category:Measurement