United States customary units

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U.S customary units is the system of units of measurement used to measure things in the United States. The system of Imperial units is similar and in some parts identical.

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: [a]

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 Americans still use the old units for daily purposes. On the other hand, world trade is conducted using the metric system and except for the US, the world uses the metric system for almost all purposes.

Length[change | change source]

unit equal to Metric
1 point (p) 0.4 mm
1 pica (P̸) 12 points 4.2 mm
1 inch (in) 6 picas 2.54 cm
1 foot (ft) 12 inches 30.48 cm
1 yard (yd) 3 feet 0.9144 m
1 mile (mi) 1760 yards 1.609344 km

Area[change | change source]

Unit Equal to Metric
1 square (survey) foot (sq ft or ft2) 9 m2
1 square chain (sq ch or ch2) 4356 sq ft 40 m2
1 acre 10 sq ch 0.4 km2
1 section 640 acres 2.6 km2
1 (survey) township (twp) 36 sections 93.2 km2

Volume[change | change source]

Capacity Volume
Unit Equal to Metric
1 cubic inch (cu in) or (in3) 16 mL
1 cubic foot (cu ft) or (ft3) 1728 cu in 28 L
1 cubic yard (cu yd) or (yd3) 27 cu ft 800 L
1 acre-foot (acre ft) 1613.333 cu yd 1,200 L
Liquid volume
Unit Equal to Metric
1 minim (min) 1 drop 0.1 mL
1 US fluid dram (fl dr) 60 min 3.7 mL
1 teaspoon (tsp) 80 min 4.92892 mL
1 tablespoon (Tbsp) 3 tsp 14.7868 mL
1 US fluid ounce (fl oz) 2 Tbsp 29.5735 mL
1 US shot (jig) 3 Tbsp 44 mL
1 US gill (gi) 4 fl oz 118.294 mL
1 US cup (cp) 2 gi 240 mL
1 (liquid) US pint (pt) 2 cp 473.176 mL
1 (liquid) US quart (qt) 2 pt 0.946353 L
1 (liquid) US gallon (gal) 4 qt 3.78541 L
1 (liquid) barrel (bbl) 31.5 gal 11.92405 L
1 oil barrel (bbl) 42 gal 15.8987 L
1 hogshead 63 gal 23.8481 L
Dry Volume
Unit Equal to Metric
1 (dry) pint (pt) 0.6 L
1 (dry) quart (qt) 2 pt 1.1 L
1 (dry) gallon (gal) 4 qt 4.4 L
1 peck (pk) 2 gal 8 L
1 bushel (bu) 4 pk 35 L
1 (dry) barrel (bbl) 3.281 bu 110 L

Mass and weight[change | change source]

Avoirdupois
Unit Equal to Metric
1 grain (gr) 60 mg
1 dram (dr) 27 11⁄32 gr 1.8 g
1 ounce (oz) 16 dr 28.3495 g
1 pound (lb) 16 oz 453.592 g
1 US hundredweight (cwt) 100 lb 45.3592 kg
1 long hundredweight 112 lb 50.802345 kg
1 short ton 20 US cwt 907.185 kg
1 long ton 20 long cwt 1,016.047 kg
Troy
Unit Equal to Metric
1 grain (gr) 65 mg
1 pennyweight (dwt) 24 gr 1.55517 g
1 troy ounce (oz t) 20 dwt 31.1035 g
1 troy pound (lb t) 12 oz t 373.242 g

Related pages[change | change source]

Notes[change | change source]

  1. Where "C" means "Celsius".