# United States US Units of Measurement Table

In these tables where foot or mile is underlined, it is survey foot or U.S. statute mile rather than international foot or mile that is meant. This section lists units of measurement that have traditionally been used in the United States. In keeping with the Omnibus Trade and Competitiveness Act of 1988, the ultimate objective is to make the International System of Units the primary measurement system used in the United States.

Units of Length
12 inches (in) = 1 foot (ft)
3 feet = 1 yard (yd)
16½ feet = 1 rod (rd), pole, or perch
40 rods = 1 furlong (fur) = 660 feet
8 furlongs = 1 U.S. statute mile (mi) = 5280 feet
1852 meters (m) = 6076.115 49 feet (approximately) = 1 international nautical mile

Units of Area

144 square inches (in2) = 1 square foot (ft2)
9 square feet = 1 square yard (yd2) = 1296 square inches
272¼ square feet = 1 square rod (rd2)
160 square rods = 1 acre = 43 560 square feet
640 acres = 1 square mile (mi2)
1 mile square = 1 section of land
6 miles square = 1 township = 36 sections = 36 square miles

Units of Volume
1728 cubic inches (in3) = 1 cubic foot (ft3)
27 cubic feet = 1 cubic yard (yd3)
Squares and cubes of customary but not of metric units are sometimes expressed by the use of abbreviations rather than symbols. For example, sq ft means square foot, and cu ft means cubic foot.

Gunter’s or Surveyors Chain Units of Measurement
0.66 foot (ft) = 1 link (li)
100 links = 1 chain (ch) = 4 rods = 66 feet
80 chains = 1 U.S. statute mile (mi) = 320 rods = 5280 feet

Units of Liquid Volume
4 gills (gi) = 1 pint (pt) = 28.875 cubic inches (in3)
2 pints = 1 quart (qt) = 57.75 cubic inches
4 quarts = 1 gallon (gal) = 231 cubic inches = 8 pints = 32 gills
When necessary to distinguish the liquid pint or quart from the dry pint or quart, the word “liquid” or the abbreviation “liq” should be used in combination with the name or abbreviation of the liquid unit.

Apothecaries Units of Liquid Volume
60 minims = 1 fluid dram (fl dr or ƒ 3) = 0.225 6 cubic inch (in3)
8 fluid drams = 1 fluid ounce (fl oz or ƒ) = 1.804 7 cubic inches
16 fluid ounces = 1 pint (pt) = 28.875 cubic inches = 128 fluid drams
2 pints = 1 quart (qt) = 57.75 cubic inches = 32 fluid ounces = 256 fluid drams
4 quarts = 1 gallon (gal) = 231 cubic inches = 128 fluid ounces = 1024 fluid drams

Units of Dry Volume
2 pints (pt) = 1 quart (qt) = 67.200 6 cubic inches (in3)
8 quarts = 1 peck (pk) = 537.605 cubic inches = 16 pints
4 pecks = 1 bushel (bu) = 2150.42 cubic inches = 32 quarts
When necessary to distinguish dry pint or quart from the liquid pint or quart, the word “dry” should be used in combination with the name or abbreviation of the dry unit.

Avoirdupois Units of Mass
[The “grain” is the same in avoirdupois, troy, and apothecaries units of mass.]
When necessary to distinguish the avoirdupois dram from the apothecaries dram, or to distinguish the avoirdupois dram or ounce from the fluid dram or ounce, or to distinguish the avoirdupois ounce or pound from the troy or apothecaries ounce or pound, the word “avoirdupois” or the abbreviation “avdp” should be used in combination with the name or abbreviation of the avoirdupois unit.
1 µlb = 0.000 001 pound (lb)
2711/32 grains (gr) = 1 dram (dr)
16 drams = 1 ounce (oz) = 437½ grains
16 ounces = 1 pound (lb) = 256 drams = 7000 grains
100 pounds = 1 hundredweight (cwt)
20 hundredweights = 1 ton (t)= 2000 pounds
In “gross” or “long” measure, the following values are recognized :
112 pounds (lb) = 1 gross or
long hundred-
weight (cwt)
20 gross or long hundredweights = 1 gross or long ton = 2240 pounds

When the terms “hundredweight” and “ton” are used unmodified, they are commonly understood to mean the 100-pound hundredweight and the 2000-pound ton, respectively; these units may be designated “net” or “short” when necessary to distinguish them from the corresponding units in gross or long measure.
General Tables of Units of Measurement
British Units of Measurement
List of all Units of Measurement
General Tables of Equivalents–Units of Length, Area and Volume

Troy Units of Mass
[The “grain” is the same in avoirdupois, troy, and apothecaries units of mass.]
24 grains (gr) = 1 pennyweight (dwt)
20 pennyweights = 1 ounce troy (oz t)= 480 grains
12 ounces troy = 1 pound troy (lb t) = 240 pennyweights = 5760 grains

Apothecaries Units of Mass
[The “grain” is the same in avoirdupois, troy, and apothecaries units of mass.]
20 grains (gr) = 1 scruple (s ap or 3)
3 scruples = 1 dram apothecaries (dr ap or 3) = 60 grains
8 drams apothecaries = 1 ounce apothecaries (oz ap or 3) = 24 scruples = 480 grains
12 ounces apothecaries = 1 pound apothecaries (lb ap) = 96 drams apothecaries
= 288 scruples = 5760 grains