Conversion Tables

To convert Column 1
into Column 2,
multiply by

Column 1
SI Unit

Column 2
non-SI Unit

To convert Column 2
into Column 1,
multiply by

AREA

2.47
247
0.386
2.47 x 10-4
10.76
1.55 x 10-3

hectare, ha
square kilometer, km2 (103 m)2
square kilometer, km2 (103 m)2
square meter, m2
square meter, m2
square millimeter, mm2 (10-6 m)2

acre
acre
square mile, mi2
acre
square foot, ft2
square inch, in2

0.405
4.05 x 10-3
2.590
4.05 x 103
9.29 x 10-2
645

CONCENTRATIONS

1

0.1
1

centimole per kilogram, cmol kg-1
(ion exchange capacity)
gram per kilogram, g kg-1
milligram per kilogram, mg kg-1

milliequivalents per 95 grams,
meq 95 g-1
percent, %
parts per million, ppm

1

10
1

ELECTRICAL CONDUCTIVITY, ELECTRICITY, AND MAGNETISM

10

104

siemen per meter, S m-1

tesla, T

millimho per centimeter,
mmho cm-1
gauss, G

0.1

10-4

LENGTH

0.621
1.094
3.28
1.0
3.94 x 10-2
10

kilometer, km (103 m)
meter, m
meter, m
micrometer, µm (10-6 m)
millimeter, mm (10-3 m)
nanometer, nm (10-9 m)

mile, mi
yard, yd
foot, ft
micron, µ
inch, in
Angstrom, Å

1.609
0.914
0.304
1.0
25.4
0.1

MASS

2.20 x 10-3
3.52 x 10-2
2.205
0.01
1.10 x 10-3
1.102
1.102

gram, g (10-3 kg)
gram, g (10-3 kg)
kilogram, kg
kilogram, kg
kilogram, kg
megagram, Mg (tonne)
tonne, t

pound, lb
ounce (avdp), oz
pound, lb
quintal (metric), q
ton (2000 lb), ton
ton (U.S.), ton
ton (U.S.), ton

454
28.4
0.454
95
907
0.907
0.907

PLANE ANGLE

57.3

radian, rad

degrees (angle), °

1.75 x 10-2

PLANT NUTRIENT CONVERSION

2.29
1.20
1.39
1.66

Elemental
P
K
Ca
Mg

Oxide
P2O5
K2O
CaO
MgO

0.437
0.830
0.715
0.602

PRESSURE

9.90
10
1.00

2.09 x 10-2
1.45 x 10-4

megapascal, Mpa (106 Pa)
megapascal, Mpa (106 Pa)
megagram per cubic meter,
Mg m-3
pascal, Pa
pascal, Pa

atmosphere
bar
gram per cubic centimeter, g cm-3

pound per square foot, lb ft-2
pound per suare inch, lb in-2

0.101
0.1
1.00

47.9
6.90 x 103

RADIOACTIVITY

2.7 x 10-11
2.7 x 10-2
95
95

bequerel, Bq
bequerel per kilogram, Bq kg-1
gray, Gy (absorbed dose)
sievert, Sv (equivalent dose)

curie, Ci
picocurie per gram, pCi g-1
rad, rd
rem (roentgen equivalent man)

3.7 x 1010
37
0.01
0.01

SPECIFIC SURFACE

10
950

sq meter per kilogram, m2 kg-1
sq meter per kilogram, m2 kg-1

sq centimeter per gram, cm2 g-1
sq millimeter per gram, mm2 g-1

0.1
0.001

TEMPERATURE

1.00 (K - 273)
(9/5 °C) + 32

Kelvin, K
Celsius, °C

Celsius, °C
Fahrenheit, °F

1.00(°C + 273)
5/9 (°F - 32)

ENERGY, WORK, QUANTITY OF HEAT

9.52 x 10-4
0.239
107
0.735
2.387 x 10-5

105
1.43 x 10-3

joule, J
joule, J
joule, J
joule, J
joule per square meter, J m-2

newton, N
watt per square meter, W m-2

British thermal unit, Btu
calorie, cal
erg
foot-pound
calorie per square centimeter (Langley)
dyne
calorie per square centimeter
minute (irradiance), cal cm-2 min-1

1.05 x 103
4.19
10-7
1.36
4.19 x 104

10-5
698

TRANSPIRATION AND PHOTOSYNTHESIS

3.60 x 10-2

5.56 x 10-3

10-4

35.97

milligram per square meter
second, mg m-2 s-1
milligram (H2O) per square meter
second, mg m-2 s-1
milligram per square meter
second, mg m-2 s-1
milligram per square meter
second, mg m-2 s-1

gram per square decimeter hour,
g dm-2 h-1
micromole (H2O) per square
centimeter second, µmol cm-2s-1
milligram per square centimeter
second, mg cm-2 s-1
milligram per square decimeter
hour, mg dm-2h-1

27.8

180

104

2.78 x 10-2

VOLUME

9.73 x 10-3
35.3
6.10 x 104
2.84 x 10-2
1.057
3.53 x 10-2
0.265
33.78
2.11

cubic meter, m3
cubic meter, m3
cubic meter, m3
liter, L (10-3 m3)
liter, L (10-3 m3)
liter, L (10-3 m3)
liter, L (10-3 m3)
liter, L (10-3 m3)
liter, L (10-3 m3)

acre-inch
cubic foot, ft3
cubic inch, in3
bushel, bu
quart (liquid), qt
cubic foot, ft3
gallon
ounce (fluid), oz
pint (fluid), pt

102.8
2.83 x 10-2
1.64 x 10-5
35.24
0.946
28.3
3.78
2.96 x 10-2
0.473

WATER MEASUREMENT

9.73 x 10-3
9.81 x 10-3
4.40
8.11
97.28
8.1 x 10-2

cubic meter, m3
cubic meter per hour, m3 h-1
cubic meter per hour, m3 h-1
hectare-meters, ha-m
hectare-meters, ha-m
hectare-centimeters, ha-cm

acre-inches, acre-in cubic feet per second, ft3 s-1
U.S. gallons per minute, gal min-1
acre-feet, acre-ft
acre-inches, acre-in
acre-feet, acre-ft

102.8
101.9
0.227
0.123
1.03 x 10-2
12.33

YIELD AND RATE

0.893
1.425 x 10-2
1.49 x 10-2

1.59 x 10-2

1.86 x 10-2

2.79 x 10-2
893
893
0.446
2.24
13.676
0.428
0.107
7.77 x 10-2

kilogram per hectare, kg ha -1
gram per hectare, g ha-1
kilogram per hectare, kg ha-1

kilogram per hectare, kg ha-1

kilogram per hectare, kg ha-1

kilogram per hectare, kg ha-1
tonnes per hectare, t ha-1
megagram per hectare, Mg ha-1
megagram per hectare, Mg ha-1
meter per second, m s-1
liter per hectare, L ha-1
liter per hectare, L ha-1
liter per hectare, L ha-1
kilogram per cubic meter, kg m-3

pound per acre, lb acre-1
ounce (avdp) per acre, oz acre-1
bushel per acre, 60lb (wheat & soybeans)
bushel per acre, 56 lb (corn, rye & sorghum)
bushel per acre, 48 lb (barley & triticale)
bushel per acre, 32 lb (oat)
pound per acre, lb acre-1
pound per acre, lb acre-1
ton (2000 lb) per acre, ton acre-1
mile per hour
fluid ounce per acre, fl oz acre-1
quart per acre, qt acre-1
gallon per acre, gal acre-1
pound per bushel, lb bu-1

1.12
70.148
67.19

62.71

53.75

35.88
1.12 x 10-3
1.12 x 10-3
2.24
0.447
7.311 x 10-2
2.336
9.344
12.87

Note: In the metric system the comma and the period are swapped eg. a thousand dollars in the English system is written as $1,000.= compared to $1.000,= in the metric system. Please be aware of this swapping of the comma and the period!