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Length

1 millimetre (mm)

0.1 centimetre = 0.01 decimetre = 0.001 metre = 1,000 microns = 0.03937 inch (about 1/25 inch)

1 centimetre (cm)

10 millimetres = 0.01 metre = 0.3937 inch = 0.03281 foot = 0.010936 yard

1 decimetre (dm)

10 centimetres = 0.1 metre = 3.937 inches

1 inch (in.)

25.4 millimetres = 2.54 centimetres = 0.0254 metre = 0.083333 foot = 0.027778 yard = 0.00505 rod

1 foot (ft)

12 inches = 0.333 yard = 0.060606 rod = 30.48 centimetres = 03048 metre = 0.16667 fathom

1 yard (yd)

36 inches = 3 feet = 0.181818 rod = 0.9144 metre = 0.00454545 furlong

1 metre

100 centimetres = 39.37 inches = 3.2808 feet = 1.09361 yards = 0.1988 rod = 0.001 kilometre = 0.5468 fathom

1 rod (r.)

5.5 yards = 16.5 feet = 198 inches = 5.02921 metres = 0.003125 mile = 0.025 furlong = 25 links

1 kilometre (km.)

1,000 metre = 3,280.8 feet = 1093.6 yards = 0.62137 mile

1 mile (mi.)

5,280 feet = 1,760 yards = 1,609.35 metres = 320 rods = 8 furlongs = 63,360 inches = 80 chains

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Slopes, Grades & Degrees

h = vertical rise

Percent grade or slope; Equals vertical rise in metres in 100m of horizontal distance.

￘ = angle of slope; angle of inclination with respect to horizontal plane,

i.e tan￘ = h/horizontal distance

Ratio of slope = horizontal distance / h

Slopes Ratio*	Percent Grade	Angle Degrees (approx.)
Flat	Flat	0
100:1	1%	1
20:1	5%	3
10:1	10%	6
5:1	20%	11
4:1	25%	13
-	30%	16
3:1	33.33%	17
-	40%	22
2:1	50%	26
-	60%	31
-	80%	38
1:1	100%	45
Vertical	Vertical	90
* Horizontal to vertical ratio

Safe Limit Restrictions (General Guide)

Slope Measurement (Plan Horizontal) to True Measure)

Example: with 2:1 slope and map measure (x) = 10m, then True Measure = 10 x 1.11180 = 11.12m

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Dilutions

1 part per million (ppm)

1m gm/L or kg = 0.0001% = 0.013 oz by weight in 100 gal = 0.379 gm in 100 gal = 1 inch in nearly 16 miles = 2 crystals of sugar in a pound = 1 oz of salt in 62,500 lb of sugar = 1 oz of sand in 31.25 tons of cement = 1 oz of dye in 7,530 gal of water = 1 lb in 500 tons = 0.007 grain per lb.

1 per cent (%)

10,000 ppm = 10 gm/L = 1.28 oz by weight per gal = 8.336 lb per 100 gal

0.1% = 1000 ppm = 1000m gm/L

0.01% = 100 ppm = 100m gm/L

0.001% = 10 ppm = 10 gm/L

0.0001% = 1 ppm = 1 m gm/L

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Pressure

1 pascal (Pa, equivalent to 1 Newton/m2) = 0.0001450 psi

1 pascal = 0.004019 inch water (60/F)

1 inch water (60/F) = 248.8 pascals

1 psi = 6894.0 pascals

psi x 0.704 = m

psi x 6.89 = kPa

psi x 0.0680 = bar, psi x 2.31 = ft

ft x 0.305 = m, ft x 0.433 = psi

m x 1.42 = psi, m x 9.80 = kPa

kPa x 0.145 = psi, kPa x 0.102 = m

bar x 14.7 = psi, bar x 10.34 = m

m x 3.28 = ft, m x 0.0967 = bar

Atmospheric Pressure

1 bar = 100,000 Pa = 105 P

(standard atmospheric pressure - 1 atm = 1.01325 bar)

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Flow

1 cu.m/sec (1,000 L/s) = 35.31 cu ft/sec

1 cu.m/sec (m3/s) = 15,850 gal/min

1m3/hr x 0.278 = L/s,1m3/hr x 16.7 = L/min

L/s x 3.60 = m3/hr,L/m x 0.060 = m3/hr

1 gal/min = 0.00006309m3sec

1 gal/min = 0.06309 l/sec

1 ft3/sec = 0.02832 m3/sec

1 ft3/sec = 28.32 l/sec

gpm x 0.272 = m3/hr

gpm x 0.0759 = L/sec

gpm x 4.55 = L/min

m3/hr x 3.68 = gpm

L/sec x 13.2 = gpm

L/min x 0.220 = gpm

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Weight

Weight is the force exerted by a mass by the acceleration due to gravity. Consider a 1m cube of fresh water. it has a mass of 1,000 kg or 1 tonne. Its weight is the vertical force on its bottom surface due to gravitational acceleration, i.e.

weight - (1000 kg/9.82m/s2) = 9810 kg/m/s1 grain (gr.)

= 9810 N

1 grain (gr.)

64.7989 mg = 0.03657 drams = 0.0020833 oz = 0.0648 gm

1 milligram (mg.)

0.001 gm = 0.015432 grain

1 gram (gm.)

1,000 m. Gm = 0.035274 oz avoirdupois = 15.42356 grains = 0.56438 dram avoirdupois = 0.0022046 lb = 0.001 kg

1 ounce avoirdupois (oz. Av.)

0.911458 oz = 28.349527 gm = 437.5 grains = 16 drams = 0.0625 lb

1 kilogram (kg.)

1,000 gm = 35.273957 oz av. = 2.20462 av. Lb = 15,432.35639 grains = 0.00098421 ton (long) = 0.0011023 ton (short)

1 ton (short)

2,000 av. Lb = 2,430.56 troy lb = 0.892857 long ton = 0.907185 metric tonne = 907.18486 kg = 32,000 oz

1 tonne (metric)

2,204 lb = 1.1023 short tons = 0.984 long ton = 1,000 kg

Metric Weight

1 grain = 0.065 gram

1 apothecaries' scruple = 1.296 grams

1 avoirdupois ounce = 28.350 grams

1 troy ounce = 31.103 grams

1 avoirdupois pound = 0.454 kilogram

1 troy pound = 0.373 kilogram

1 gram = 15.432 grains

1 gram = 0.772 apothecaries' scruple

1 gram = 0.035 avoirdupois ounce

1 gram = 0.032 tray ounce

1 kilogram = 2.205 avoirdupois pounds

1 kilogram = 2.679 tray pounds

Temperature

Degrees Fahrenheit (ﾰF - 32) x 0.555 = degrees Celsius (ﾰC)

 

Fahrenheit to Centigrade	Centigrade to Fahrenheit
Deg. F to Deg. C	Deg. C to Deg. F
- 40 = - 40	- 40 = - 40
- 30 = - 34.4	- 30 = - 22
- 20 = - 28.9	- 20 = - 4
- 10 = - 23.3	- 10 = +14
0 = - 17.8	0 = + 32
+10 = - 12.2	+10 = +50
+20 = - 6.67	+20 = +68
+32 = 0.00	+30 = +86
+50 = +10.0	+50 = +122
+60 = +15.6	+60 = +140
+80 = +26.7	+80 = +176
+100 = +37.8	+100 = +212
+212 = +100.0

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Volume

English System to	Metric System
Unit	Multiplied by	Equals
Cubic Inches	x 16.4	= Cubic Centimetres
Cubic Feet	x 0.0283	= Cubic Metres
Cubic Yards	x 0.765	= Cubic Metres
Metric System to	English System
Unit	Multiplied by	Equals
Cubic Centimetres	x 0.06	= Cubic Inches
Cubic Metre	x 35.3	= Cubic Feet
Cubic Metres	x 1.31	= Cubic Yard

1 cubic centimetre (c.cm)

0.06102 cu.in = 1,000 cu.mm = 0.000001 cu.m

1 cubic (cu.in)

16.38716 cu.cm - 0.0005787 cu ft = 0.004329 gal

1 cubic foot (cu.ft.)

0.80356 bushel = 1.728 cu in = 0.037037 cu yd = 0.028317 cu.m = 7.4805 US gal = 6.229 British gal =

28.316L = 29.922 quart (liquid) = 25.714 quarts (dry)

1 cubic foot (cu.ft.) of water

62.43 lb (1 lb of water = 27.68 cu.in = 0.1198 US gal = 0.01602 cu.ft)

1 cubic foot (cu.ft.) of dry soil

sandy (90 lb), loamy (100 lb), clayey (75 lb)

1 bushel (bu.) dry soil

sandy (112 lb), loamy (100 lb), clayey (94 lb)

1 cubic yard (cu.yd.)

27 cu.ft = 46,656 cu.in = 764.559 L = 202 US gal = 168.17 British gal = 1,616 pints (liquid) = 807.9 quarts (liquid) = 21.694 bushels = 0.764559 cu.m

1 cubic metre (cu.m.)

1.30794 cu.yd = 35.3144 cu.ft = 28.3776 bushels = 264.173 gal = 1.000 cu m = 1,056.7 quarts (liquid) = 2,113.4 pints (liquid) = 61,023 cu.in = 1 x 106 cu cm

1 millilitre (mL.)

1 cu.cm = 0.1 dL = 0.001 L = 0.061 cu in =0.0084538 gill = 0.03815 fl.oz

1 fluid ounce (fl.oz)

2 tablespoons = 0.125 cup = 0.0625 pint = 0.03125 quart = 0.00781 gal = 29.573 mL = 1.80469 cu.in = 8 fluid drams = 0.25 gill = 0.029573 L

1 cup

16 tablespoons = 8 fl oz = 0.5 pint = 2 gills = 236.6 cu cm or mL

1 pint (pt)

16 fl oz = 32 tablespoons = 2 cups = 4 gills = 0.125 gal = 473.167 mL = 1.04 lbs of water = 28.875 cu in = 0.473167 L = 128 fl drams = 0.0167 cu ft

1 litre (L)

2.1134 pints = 1.0567 liquid quarts (US) = 0.9081 dry quarts (US) = 0.264178 gal (US) = 10 dL = 1,000 ml or cu cm = 33.8147 fl oz = 270.5179 fl drams = 61.025 cu in = 0.0353 cu ft = 0.028378 bushel = 0.001308 cu yd

1 quart (qt.)

2 pints = 4 cups = 8 gills = 32 fl. oz = 57.749 cu in = 64 tablespoons = 0.25 gal = 0.946333L = 0.3342 cu ft = 256 fluid drams

1 gallon (gal) US

4 quarts = 8 pints = 128 fl oz = 0.1337 cu ft = 0.83268 British gal = 3,785.4 ml or cu cm = 231 cu in = 8.337 lbs of water = 3.782 kg = 9810 N

Area

1 square millimetre (sq. Mm.)

0.01 sq cm = 0.000001 sq m = 0.00155 sq in.

1 square centimetre (sq.cm.)

100 sq mm = 0.155 sq inch = 0.001076 sq ft

1 square inch (sq.in.)

6.451626 sq cm = 0.0069444 sq ft

1 square foot (sq. Ft.)

144 sq inches = 0.111111 sq yd = 0.0929 sq m = 0.003673 sq rod

1 square yard (sq.yd.)

9 sq ft = 1,296 sq inches = 0.83613 sq m = 0.03306 sq rod

1 square metre (sq. m.)

10.76387 sq ft. = 1,550 sq in = 1.195985 sq yd = 0.039537 sq rod = 1 x 106 sq mm = 10,000 sq cm

1 sq.rod (sq.r.)

30.25 sq.yd = 25.29295 sq.m = 272.25 sq.ft = 0.00625 sq.acre = 0.0025293 hectare = 625 sq.links

1 acre (A.)

43,560 sq.ft = 4840 sq.yd = 160 sq.rod = 4,046.873 sq.m = 0.404687 ha. = 0.0015625 sq.mile = 10 sq.chain = 8 ft.wide strip by 1 mile long (approx.)

1 hectare (ha.)

2,471 acres = 395.367 sq.rods = 10,000 sq m = 0.01 sq.km = 0.0039 sq.mile

1 square kilometre (sq.km.)

0.3861 sq mile = 247.1 acres = 100 ha = 1 x 106 sq.m

1 square mile

640 acres = 1 section = 258.9998 ha. = 102,400 sq.rods = 3,097,600 sq yd = 2.589 x 106 sq.m

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Miscellaneous Conversions