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Publication #AGR39

Metric System Conversion Factors1

J. Bryan Unruh, Barry J. Brecke, and Ramon G. Leon-Gonzalez2

Area Equivalents

1 Acre (A)

= 43,560 square feet (ft2)
= 4,840 square yards (yd2)
= 0.405 hectares (ha)
= 160 square rods (rd2)
= 4,047 square meters (m2)

1 Acre-inch (ac-in)

= 102.8 cubic meters (m3)
= 27,154 gallons, US (gal)
= 3,630 cubic feet (ft3)

1 Are (a)

= 100 square meters (m2)
= 119.6 square yards (yd2)
= 0.025 acre (A)

1 Cubic Foot (ft3)

= 1,728 cubic inches (in3)
= 0.037 cubic yards (yds3)
= 0.02832 cubic meters (cm3)
= 28,320 cubic centimeters (cm3)

1 Cubic Yard (yd3)

= 27 cubic feet (ft3)
= 0.764 cubic meters (m3)

1 Hectare (ha)

= 10,000 square meters (m2)
= 100 are (a)
= 2.471 acres (A)

1 Square Foot (ft2)

= 144 square inches (in2)
= 929.03 square centimeters (cm2)
= 0.0929 square meters (m2)

1 Square Mile (mi2)

= 27,878,400 square feet (ft2)
= 3,097,600 square yards (yd2)
= 640 square acres (A2)
= 2,589,988.11 square meters (m2)

1 Square Rod (rd2)

= 39,204 square inches (in2)
= 272.25 square feet (ft2)
= 30.25 square yards (yds2)
= 25.3 square meters (m2)

1 Square Yard (yd2)

= 9 square feet (ft2)
= 0.836 square meters (m2)

Flow Equivalents

1 Gallon Per Minute (GPM, gal/min)

= 0.134 cubic feet/minute (CFMft3/min)

1 Cubic Foot Per Minute (CFM, ft3/min)

= 449 gallons per hour (GPH)
= 7.481 gallons per minute (GPM)

Length Equivalents

1 Centimeter (cm)

= 0.3937 inch (in)
= 0.01 meter (m)
= 0.03281 foot (ft)

1 Chain, Gunter's or Surveyor's (ch)

= 792 inches (in)
= 66 feet (ft)
= 22 yards (yd)
= 4 rods (rd)
= 0.0125 miles (mi)
= 2011.68 centimeters (cm)
= 20.116 meters (m)

1 Foot (ft)

= 12 inches (in)
= 30.48 centimeters (cm)
= 0.3048 meters (m)

1 Inch (in)

= 0.08333 foot (ft)
= 25.4 millimeters (mm)
= 2.54 centimeters (cm)
= 0.0254 meters (m)

1 Kilometer (km)

= 39,370 inches (in)
= 3,281 feet (ft)
= 0.621 U.S. statute mile (mi)
= 100,000 centimeters (cm)
= 1,000 meters (m)

1 Meter (m)

= 39.4 inches (in)
= 3.28 feet (ft)
= 1.094 yards (yd)
= 1000 millimeters (mm)
= 100 centimeters (cm)

1 Micrometer (micron, µm)

= 0.001 millimeters (mm)
= 1 x 10-3 millimeters (mm)

1 Rod (rd)

= 198 inches (in)
= 16½ feet (ft)
= 5½ yards (yd)
= ¼ chain (ch)
= 502.92 centimeters (cm)
= 5.03 meters (m)

1 Statute Mile (mi)

= 5,280 feet (ft)
= 1,760 yards (yd)
= 1,609 meters (m)
= 1.61 kilometers (km)

1 Yard (yd)

= 36 inches (in)
= 3 feet (ft)
= 0.9144 meters (m)

Liquid Equivalents

1 Acre-inch of Water (ac in)

= 27,154 gallons (gal)
= 3,630 cubic feet (ft3)

1 Cubic Foot of Water (ft3)

= 7.48 gallons, US (gal)
= 62.4 pounds, US (lb, #)
= 28.3 liters (L)

1 Cup, measuring (c)

= 8 fluid ounces (fl. oz.)
= ½ pint (pt)
= 16 tablespoons (tbsp)
= 236.6 milliliters (ml)

1 Fluid Ounce, US (fl. oz.)

= 6 teaspoons (tsp)
= 2 tablespoons (tbsp)
= 29.57 milliliters (ml)

1 Gallon, US (gal)

= 4 quarts (qt)
= 8 liquid pints (pt)
= 16 cups (c)
= 256 tablespoons (tbsp)
= 128 fluid ounces, US (fl. oz.)
= 8.337 pounds, US (lb, #) of water
= 3.785 liters (L)
= 3,785 milliliters (ml)
= 0.1337 cubic foot (ft3)
= 231 cubic inches (in3)
= 0.8333 Imperial gallon

1 Liquid Pint, US (pt)

= 2 cups (c)
= 32 tablespoons (tbsp)
= 16 fluid ounces, US (fl. oz.)
= 473.2 milliliters (ml)

1 Liquid Quart, US (qt)

= 2 liquid pints, US (pt)
= 4 cups (c)
= 64 tablespoons (tbsp)
= 32 fluid ounces, US (fl. oz.)
= 57.75 cubic inches (in3)
= 0.9463 liters (L)

1 Liter (L)

= 1,000 milliliters (ml)
= 33.8 fluid ounces, US (fl. oz.)
= 2.1 liquid pints, US (pt)
= 1.057 liquid quarts, US (qt)
= 0.26 gallons, US (gal)

1 Milliliter (mL)

= 1 cubic centimeter (cm3)
= 0.034 fluid ounces, US (fl. oz.)
= 0.002 liquid pint, US (pt)

1 Tablespoon (tbsp)

= 3 teaspoons (tsp)
= 14.8 milliliters (ml)
= ½ fluid ounces, US (fl. oz.)

1 Teaspoon (tsp)

= 80 drops
= 0.1667 fluid ounces, US (fl.oz.)
= 4.93 milliliters (ml)

Mixture Proportions

1 pint/100 gallons = 1 teaspoon/1 gallon
1 quart/100 gallons = 2 tablespoons/1 gallon

Pressure Equivalents

1 pound per square inch (PSI) = 6.9 kilopascal (kPa)

Temperature Equivalents

Convert degrees Centigrade (°C) to degrees Fahrenheit (°F)

degrees CentigradeC) = (°F - 32) x 5/9

Convert degrees Fahrenheit (°F) to degrees Centigrade (°C)

degrees Fahrenheit F) = (°C x 9/5) + 32

Weight Equivalents

1 Ton, US, short or net

= 2,000 pounds, US (lb, #)
= 0.907 metric tons
= 907.2 kilograms (kg)

1 Metric Ton

= 1,000 kilograms (kg)
= 106 (1 million) grams (g)
= 2,205 pounds, US (lb, #)

1 Pound, US (lb, #)

= 16 ounces, weight (oz.)
= 7,000 grains
about 1 liquid pint (pt)
= 453.6 grams (g)
= 0.4536 kilograms (kg)

1 Ounce, weight (oz.)

= 28.35 grams (g)

1 Kilogram (kg)

= 1,000 grams (g)
= 35.3 ounces, weight (oz.)
= 2.205 pounds, US (lb, #)

1 Gram (g)

= 1,000 milligrams (mg)
= 0.001 kilograms (kg)
= 0.035 ounces, weight (oz.)
= 0.0022 pounds, US (lb, #)

1 Milligram (mg)

= 0.001 grams (g)
= 10-3 grams (thousandth)

1 Microgram (µg)

= 0.001 milligrams (mg)
= 10-6 grams (millionth)

1 Nanogram (ng)

= 0.001 micrograms (µg)
= 10-9 grams (billionth)

1 Picogram (pg)

= 10-12 grams (trillionth)

1 Part Per Billion (ppb)

= 1 nanogram per gram (ng/g)
= 1 microgram per kilogram (µg)/kg)
= 1 microgram per liter (µg/L)

1 Part Per Million (ppm)

= 1 milligram per liter (mg/L)
= 1 milligram per kilogram (mg/kg)
= 1 microgram per gram (µg/g)
= 0.0001 percent (%)
= 0.013 fluid ounces per 100 gallon water

1 Part Per Trillion (ppt)

= 1 picogram per gram (pg/g)

1 Percent (%)

= 10,000 parts per million (ppm)
= 10 grams per liter (g/L)
= 1.33 ounces (oz.) by weight per 1 gallon water
= 8.34 pounds (lb, #) per 100 gallons water

MIXTURE RATIOS

1 milligram per gram (mg/g) = 1,000 parts per million (ppm)
1 fluid ounce, US per 1 gallon, US (1 fl. oz./1 gal) = 7,490 parts per million (ppm)
1 fluid ounce, US per 100 gallons, US (1 fl. oz./100 gal) = 75 parts per million (ppm)

SLOPES

10% = 6° = 10:1
18% = 10° = 6:1
25% = 14° = 4:1
33% = 18° = 3:1
50% = 26° = 2:1
100% = 45° = 1:1

Tables

Table 1. 

Metric prefix definitions, multiples, and equivalents

PREFIX

MULTIPLE

EQUIVALENT

tera -

1012

trillionfold

giga -

109

billionfold

mega -

106

millionfold

kilo -

103

thousandfold

hecto -

102

hundredfold

deca -

101

tenfold

PREFIX

SUBMULTIPLE

EQUIVALENT

deci -

10-1

tenth

centi -

10-2

hundredth

milli -

10-3

thousandth

micro -

10-6

millionth

nano -

10-9

billionth

pico -

10-12

trillionth

Note: basic metric unit = 1

Table 2. 

Conversion factors

TO CONVERT

MULTIPLY BY

TO OBTAIN

Acres

43,560

Square Feet (ft2)

Acres

0.00405

Square Kilometer (km2)

Acres

4050

Square Meter (m2)

Acres

4840

Square Yards (yd2)

Acre-Feet

324,851

Square Feet (ft2)

Acre-Feet

43,560

Cubic Feet (ft3)

Acre-Feet

1233.5

Cubic Meters (m3)

Bar

14.5

Pounds Per Square Inch (psi, lb/sq.in., #/in2)

Bar

1019.7

Grams Per Cubic Centimeters (g/cm3)

Bar

29.53

Inches of Mercury at Zero Degrees Centigrade (in hg @ o¡c)

Centimeters (cm)

0.03281

Feet (ft)

Centimeters

0.3937

Inches (in)

Centimeters

0.1094

Yards (yd)

Centimeters

0.01

Meters (m)

Centimeters

10

Millimeters (MM)

Centimeters Per Second (cm/sec)

1.9685

Feet Per Minute (ft/min)

Centimeters Per Second (cm/sec)

0.0223694

Miles Per Hour (mph)

Cubic Centimeters (cm3)

0.0610237

Cubic Inches (in3)

Cubic Feet (ft3)

0.0283

Cubic Meter (m3)

Cubic Feet

7.4805

Gallons (gal)

Cubic Feet

1728

Cubic Inches (in3)

Cup

8

Fluid Ounces (fl oz.)

Feet (ft)

30.48

Centimeters (cm)

Feet

0.3048

Meters(m)

Foot Candle

10.764

Lux

Gallons (gal)

3.785

Liters (l)

Gallons

3,785

Milliliters (ml)

Gallons

128

Ounces, Liquid (fl oz.)

gal/Acre (GPA)

9.354

Liters/Hectare (l/ha)

gal/1000 ft2

4.0746

Liters/100 Square Meters (l/100m3)

GAL/Minute (gpm)

2.228 X 10-3

Cubic Feet/Second (ft3/sec)

Grams (g)

0.002205

Pounds, US (lbs, #)

Grams

0.0235274

Ounces, US Weight (oz.)

Grams Per Liter (g/l)

1,000

ppm

Grams Per LITER (g/l)

10

Percent (%)

Grams/Square Meter (g/m2)

0.00020481

Pounds Per Square Feet (lb/sq ft, #/ft2)

Grams Per Cubic Meter (g/cm3)

0.036127

Pounds Per Cubic Inch (lb/in3)

Grams Per Cubic Meter (g/cm3)

62.428

Pounds Per Cubic Foot (lb/ft3)

Hectares (ha)

2.471

Acres (A)

Inches

2.540

Centimeters (cm)

Inches

0.0254

Meters (m)

Inches

25.40

Millimeters (mm)

Square Inches (in2)

6.4516

Square Centimeters (cm2)

Cubic Inches (in3)

16.3871

Cubic Centimeters (cm3)

Kilograms (kg)

2.2046

Pounds, US (lbs, #)

Kilograms/Hectare (kg/ha)

0.892

Pounds/Acre

Kilograms/Hectare (kg/ha)

0.02048

Pounds Per 1000 Square Feet (lb/1000 ft2)

Kilogram Per Liter (kg/l)

8.3454

Pounds Per Gallon (lb/gal)

Kilometers (km)

100,000

Centimeters (cm)

Kilometers

3,281

Feet (ft)

Kilometers

1,000

Meters (m)

Kilometers

0.6214

Miles (mi)

Kilometers

1,094

Yards (yd)

Kilometers Per Hour (km/h)

0.62137

Miles Per Hour (mph)

Kilometers Per Hour (km/h)

54.6807

Feet Per Minute

Liters (l)

0.2642

Gallons (gal)

Liters

2.113

Pints (pt)

Liters

1.057

Quarts (qt)

Liters/Acre

0.107

Gallons/Acre

Liters/100 Square Meters (l/100 m2)

0.2454

Gallons/1000 Square Feet (gal/1000ft2)

Liters/Hectare (l/ha)

0.107

Gallons Per Acre

Meters (m)

3.281

Feet (ft)

Meters

39.37

Inches (in)

Meters

1.094

Yards (yd)

Meters

100

Centimeters (cm)

Meters

0.001

Kilometers (km)

Meters

1,000

Millimeters (mm)

Meters Per Second (m/sec)

2.2369

Miles Per Hour (mph)

Square Meters (m2)

10.764

Square Feet (ft2)

Cubic Meters (m3)

35.3147

Cubic Feet (ft3)

Cubic Meters (m3)

1.30795

Cubic Yards (yd3)

Miles (mi)

160,900

Centimeters (cm)

Miles

5280

Feet (ft)

Miles

1.609

Kilometers (km)

Miles

1760

Yards (yd)

Miles/Hour (mph)

1.467

Feet/Second (ft/sec)

Miles/Hour

88

Feet/Minute (ft/min)

Miles/Hour

1.61

Kilometers/Hour (km/hr)

Miles/Hour

0.447

Meter/Second (m/sec)

Milliliters (ml)

0.0338

Ounces, Fluid (fl oz.)

Millimeters (mm)

0.03937

Inches (in)

Ounces, Fluid (fl. oz.)

0.02957

Liters (l)

Ounces, Fluid (fl. oz.)

29.573

Milliliters (ml)

Ounces, US, Weight (oz.)

28.35

Grams (gm)

Parts Per Million (ppm)

2.719

Pounds of Active Ingredient (lb ai)/Acre-foot of Water

PPM

0.001

Grams/Liter (gm/l)

PPM

8.34

Pounds/Million gal (lb/Mgal)

PPM

1

Milligrams/Kilograms (mg/kg)

PPM

0.013

Ounces/100 gal of Water

PPM

0.3295

Gallons/Acre-foot of Water

PPM

8.345

Pounds/Million gal of Water

Percent (%)

10

Grams/Kilograms (g/kg)

Pint, Liquid (pt.)

0.473

Liter (l)

Pint Per Acre (pt/a)

1.1692

Liter Per Hectare (l/ha)

Pounds, US (lb, #)

0.4536

Kilograms (kg)

Pounds

453.6

Grams (g)

Pounds/Acre

1.12

Kilograms/Hectare (km/ha)

Pounds/Acre (lb/a)

0.02296

Pounds Per 1000 Square Feet (lb/1000 ft2)

Pounds/Square Feet (lb/ft2)

4883

Grams/Square meter (gm/m2)

Pounds/Gallon

0.12

Kilogram/Liter (kg/l)

PSI; Pounds Per Square Inch (lbs/in2)

6.9

Kilopascals (kPa)

PSI

0.06895

Bar

PSI

0.062046

Atmosphere (atm)

Quarts, Liquid (qt)

0.9463

Liters (l)

Quarts Per Acre (qt/a)

2.3385

Liters Per Hectare (l/ha)

Square Centimeters (cm2)

0.001076

Square Feet (ft2)

Square Centimeters

0.1550

Square inches (in2)

Square Feet (ft2)

929

Square Centimeters (cm2)

Square Feet

0.0929

Square Meters (m2)

Square Feet

9.294 X 10-6

Hectares (ha)

Square Inch

6.452

Square Centimeters (cm2)

Ton (2000 lbs)

907

Kilograms (kg)

Yards (yd)

91.44

Centimeters (cm)

Yards

0.9144

Meters (m)

Yards

914.4

Millimeters (mm)

Cubic yards (Yd3)

0.7645

Cubic Meters (m3)

Phosphoric Acid (P2O5)

0.437

Phosphorus (P)

Potassium Oxide (K2O)

0.830

Potassium (K)

Calcium Oxide (CaO)

0.715

Calcium (Ca)

Magnesium Oxide (MgO)

0.602

Magnesium (Mg)

Table 3. 

Decimal and millimeter length equivalents.

FRACTION (inch) =

DECIMALS (inch) =

MILLIMETERS

1

1.00

25.4

15/16

0.9375

23.812

7/8

0.875

22.225

13/16

0.8125

20.638

3/4

0.75

19.05

11/16

0.6875

17.462

5/8

0.625

15.875

9/16

0.5625

14.288

1/2

0.5

12.70

7/16

0.4375

11.112

3/8

0.3750

9.525

11/32

0.34375

8.731

5/16

0.3125

7.938

9/32

0.28125

7.144

1/4

0.25

6.350

15/64

0.234375

5.953

7/32

0.21875

5.556

13/64

0.203125

5.159

3/16

0.1875

4.762

11/64

0.171875

4.366

5/32

0.15625

3.969

9/64

0.140625

3.572

1/8

0.1250

3.175

7/64

0.109375

2.778

3/32

0.09375

2.381

5/64

0.078125

1.984

1/16

0.0625

1.588

3/64

0.046875

1.191

1/32

0.03125

0.794

1/64

0.015625

0.397

Footnotes

1.

This document is AGR39, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date November 1993. Revised December 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

J. Bryan Unruh, associate center director and professor, Department of Environmental Horticulture; Barry J. Brecke, adjunct professor, Department of Agronomy; and Ramon G. Leon-Gonzalez, West Florida Research and Education Center; Department of Agronomy, UF/IFAS Extension, Gainesville, FL 32611.


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U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.