LENGTH
Ordinary Units
1 foot = 12 inches
1 yard = 3 feet
1 mile = 5280 feet
1 nautical mi. = 1.1516 statute mi.
1 acre = 208.71 ft. on one side of square
Metric Units
10 millimeters (mm.) = 1 centimeter (cm.)
10 cm. = 1 decimeter (dm.)
10 dm. = 1 meter (m.)
1000 m. - 1 kilometer (about 5/8 mi.) (km.)
Equivalents
| 1 inch | = 2.5400 centimeters |
| 1 foot | = 0.3048 meters |
| 1 statute mi. | = 1.60935 kilometers |
| 1 nautical mi. | = 1.853 kilometers |
| 1 centimeter | = 0.39370 inches |
| 1 meter | = 3.28 feet |
| 1 kilometer | = 3280.83 feet = 0.62137 mil |
Ordinary Units
| 1 square foot | = 144 square inches |
| 1 square yard | = 9 sq. ft. |
| = 1296 sq. in. | |
| 1 acre | = 43,560 sq. ft. |
| = 4840 sq. yds. | |
| 1 sq. mile | = 27,878,400 sq. ft. |
| = 3,097,600 sq. yds. | |
| = 640 acres | |
| = 1 section of land (U.S.) |
Equivalents
| 1 square centimeter | = 0.155 square inch |
| 1 square meter | = 10.76 square feet |
| = 1.196 square yards | |
| 1 hectare | = 2.47 acres |
| 1 square kilometer | = 0.386 square mile |
| 1 square inch | = 6.45 square centimeters |
| 1 square foot | = 0.0929 square meter |
| 1 square yard | = 0.836 square meter |
| 1 acre | = 0.405 hectare |
| 1 square mile | = 2.59 square kilometers |
VOLUME AND CAPACITY
Ordinary Units
| 1 cu.ft. of water at 39.1°F. = 62.425 lbs. | |
| 1 United States gallon = 231 cu.in. | |
| 1 imperial gallon = 277.274 cu.in. | |
| 1 cubic inch of water = 0.004329 U.S. gallon | |
| = 0.003607 imperial gallon | |
| = 0.036126 pound | |
| 1 cubic foot of water = 1728 cu.in. | |
| = 7.480519 U.S. gallons | |
| = 6.232103 imperial gallons | |
| = 62.4250 pounds | |
| 1 cubic yard | = 27 cu.ft. = 46,656 cu.in. |
| 1 pint | = 4 gills |
| 1 quart | = 2 pints |
| 1 gallon | = 4 quarts |
| 1 U.S. gallon | = 231 cu.in. |
| = 0.133681 cu.ft. | |
| = 0.083311 imperial gallon | |
| = 8.345 lbs. | |
| 1 barrel | = 31.5 gallons = 4.21 cu.ft. |
| 1 U.S. bushel | = 1.2445 cu.ft. |
| 1 fluid ounce | = 1.8047 cu.in. |
| 1 acre foot | = 43,560 cu.ft. |
| = 1,613.3 cu.yds. | |
| = 2,700,000 pounds | |
| 1 acre inch | = 3,630 cu.ft. |
| 1 million U.S. gallons | = 133,681 cu.ft. |
| 3,0689 acre-ft. | |
| 1 ft. depth on 1 sq.m. | = 27,878,400 cu.ft. |
| = 640 acre-ft. |
| 1 inch depth on 1 sq.mi. | = 2,323,200 cu.ft. |
| = 53,333 acre-ft. |
Metric Units (liquid capacity)
| 1 centiliter (cl.) | = 10 milliliters (ml.) |
| 1 deciliter (dl.) | = 10 centiliters |
| 1 liter (l.) | = 10 deciliters (about 1 quart) |
| 1 dekaliter (dkl.) | = 10 liters |
| 1 hectoliter (hl.) | = 10 dekaliters |
| 1 kiloliter | = 10 hectoliters |
Equivalents
| 1 cu.in. | = 16.387 cu.cm. |
| 1 cu.ft. | = 0.0283 cu.m. |
| 1 cu.yd. | = 0.765 cu.m. |
| 1 cu.cm. | = 0.1610 cu.in. |
| 1 cu.m. | = 35.3 cu.ft. |
| = 1.308 cu.yds. | |
| 1 liter | = 61.023378 cu.in. |
| = 0.035314 cu.ft. | |
| = 0.264170 U.S. liquid gallon | |
| = 0.2201 imperial gallon | |
| 1 milliliter = 0.0338 liquid ounce | |
| 1 U.S. liquid ounce = 29.57 milliliters | |
| 1 U.S. liquid quart = 0.946 liters | |
| 1 U.S. liquid gallon = 3.785 liters | |
WEIGHT
English Units
| 1 pound = 16 ounces (avoirdupois) | |
| 1 ton = 2000 lbs. | |
| 1 long ton = 2240 lbs. | |
| 1 lb. of water (39.1°F.) | = 27.681217 cu.in. |
| = 0.016019 cu.ft. | |
| = 0.119832 U.S. gallon | |
| = 0.099833 imperial gallon | |
| = 0.453617 liter | |
Metric Units
| 1 centigram (cg.) | = 10 milligrams (mg.) |
| 1 decigram (dg.) | = 10 centigrams |
| 1 gram (g.) | = 10 decigrams (about 15 grains) |
| 1 dekagram (dkg.) | = 10 grams |
| 1 hectogram (hg.) | = 10 dekagrams |
| 1 kilogram (kg.) | = 10 hectograms |
| 1 metric ton | = 1000 kilograms |
Equivalents
| 1 gram | = 15.43 grains |
| = 0.0353 avoirdupois ounce | |
| 1 kilogram | = 2.205 avoirdupois pounds |
| 1 metric ton | = 0.984 gross or long ton |
| = 1.102 net or short tons | |
| 1 avoirdupois ounce | = 28.35 grams |
| 1 avoirdupois pound | = 0.4536 kilogram |
PRESSURE
Comparison of Heads of Water in Feet with Pressures in Various Units
| One foot of water at 39.1°F. | = 62.425 pounds per square foot |
| = 0.4335 pounds per square inch | |
| = 0.0295 atmosphere | |
| = 0.8826 inch of mercury at 30°F. | |
| = 773.3 feet of air at 32°F. and atmospheric pressure | |
| One pound on the square foot, at 39.1°F. = 0.01602 foot of water | |
| One pound on the square inch, at 39.1°F. = 2.307 feet of water | |
| One atmosphere of 29.992 inches of mercury = 33.9 feet of water | |
| One inch of mercury 32°F. = 1.133 feet of water | |
| One foot of air at 32°F. and 1 atmosphere = 0.001293 foot of water | |
| One foot of average sea water = 1.026 feet of pure water | |
| One foot of water at 62°F. | = 62.355 pounds per square foot |
| = 0.43302 pounds per square inch | |
| One inch of water at 62°F. | = 0.5774 ounce = 0.036085 pound per square inch |
| One pound of water on the square inch at 62°F. = 2.3094 feet of water | |
| 1 atmosphere at sea level (32°F.) | = 14.697 lbs. per sq.in. |
| = 29.921 in. of mercury | |
| 1 inch of mercury (32°F.) = 0.49119 lb. per sq.in. | |
FLOWING WATER
| C.F.S. | = | cubic feet per second, or second feet |
| G.P.M. | = | gallons per minute |
| 1.0 F.S. | = | 60 cu.ft. per min. |
| = | 86,400 cu.ft. per 24 hrs. | |
| = | 448.83 U.S. gals. per min. | |
| = | 646,317 U.S. gals. per 24 hrs. | |
| = | 1.9835 acre-foot per 24 hrs. (usually taken as 2) | |
| = | 1 acre-inch per hour (approximate) | |
| = | .028317 cu.meters per second | |
| = | 2446.59 cu.meters per day |
MISCELLANEOUS
Temperature
| Freezing point of water | = 32° Fahrenheit |
| = 0° Centigrade |
| Boiling point of water (at normal air pressure) | = 212°Fahrenheit |
| = 100°Centigrade |
1 degree Fahrenheit = 0.5556 degree (Centigrade)
Convert Fahrenheit to Centigrade: X°F - 32 (0.5556)
1 degree Centigrade = 1.8 degrees Fahrenheit
Convert Centigrade to Fahrenheit: X°C (1.8) + 32
Circular Measure
| 1 minute (') | = 60 seconds (") |
| 1 degree (o) | = 60 minutes |
| 1 right angle | = 90 degrees |
| 1 circumference | = 360 degrees |
Time Measure
| 1 minute | = 60 seconds |
| 1 hour | = 60 minutes = 3600 seconds |
| 1 day | = 24 hours = 1440 minutes |
| 1 week | = 7 days |
| 1 year | = 365 days, 5 hrs., 48 min., 48 sec. |
