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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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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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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

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Temperature

Degrees Celsius (?C x 1.8) + 32 = degrees Fahrenheit (?F)

Degrees Fahrenheit (?F - 32) x 0.555 = degrees Celsius (?C)

 

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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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

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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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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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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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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)

Percent Grade	Restriction Guide
100% (1:1)	Maximum cut slope.
50% (2:1)	Maximum fill slope.
33.33% (3:1)	Maximum for simple construction.
30%	Maximum for practical landscape care, use retaining walls where practical.
20%	Maximum lawn slope.
15%	Consider ground cover or shrubs to replace lawn.
12%	Maximum driveway slope.
10%	Step grade - maximum where snow or ice.
5% (20:1)	Maximum for dirt roads and highway traffic. Optimum drain slope from buildings.
3%	Maximum freeway slope (rolling).
2%	Optimum for playfields - other flat landscapes.
1% (100:1)	Minimum landscape slope.

Slope Measurement (Plan Horizontal) to True Measure)

Slope ratio:Horizontal to vertical	Map Measure	Multiplied by Factor
3/4 to 1	x	1.667
1 to 1	x	1.4142
1-1/2 to 1	x	1.2019
2 to 1	x	1.11180
2-1/2 to 1	x	1.0770
3 to 1	x	1.0541
4 to 1	x	1.0198

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

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Miscellaneous Conversions

Multiply	By	To Get		Multiply	By	To Get
Acres	43,560	Square feet		Metres	3.2181	Feet
Acres	160	Square rods		Metres	39.37	Inches
Acres	4840	Square yards		Miles	5,280	Feet
Bushels	4	Pecks		Miles	63,360	Inches
Bushels	64	Pints		Miles	320	Rods
Bushels	32	Quarts		Miles	1,760	Yards
Centimetres	0.3937	Inches		Miles per hour	88	Feet per minute
Centimetres	0.01	Metres		Miles per hour	1.467	Feet per second
Cubic Centimetres	0.03382	Ounces (liquid)		Miles per minute	60	Miles per hour
Cubic feet	1.728	Cubic Inches		Ounces (dry)	0.0625	Pounds
Cubic feet	0.03704	Cubic Yards		Ounces (liquid)	0.0625	Pints (liquid)
Cubic feet	7.4805	Gallons		Ounces (liquid)	0.03125	Quarts (liquid)
Cubic feet	29.92	Quarts (liquid)		Pecks	16	Pints (dry)
Cubic yards	27	Cubic feet		Pecks	8	Quarts (dry)
Cubic yards	46,656	Cubic inches		Pints (dry)	0.5	Quarts (dry)
Cubic yards	202	Gallons		Pints (liquid)	16	Ounces (liquid)
Feet	30.48	Centimetres		Pounds	453.5924	Grams
Feet	12	Inches		Pounds	16	Ounces
Feet	0.3048	Metres		Pounds of water	0.1198	Gallons
Feet	0.060606	Rods		Quarts (liquid)	0.9463	Litres
Feet	1/3 or 0.33333	Yards		Quarts (liquid)	32	Ounces (liquid)
Gallons	0.1337	Cubic Feet		Quarts (liquid)	2	Pints (liquid)
Gallons	4	Quarts (liquid)		Rods	16.5	feet
Gallons of water	8.0453	Pounds of water		Rods	5.5	Yards
Grams	15.43	Grains		Square feet	144	Square inches
Rams	0.001	Kilograms		Square feet	0.1111	Square yards
Grams	1,000	Milligrams		Square inches	0.00694	Square feet
Grams	0.0353	Ounces		Square miles	640	Acres
Grams per litre	1,000	Parts per million		Square miles	27,878,400	Square feet
Inches	2.54	Centimetres		Square rods	0.00625	Acres
Inches	0.08333	Feet		Square rods	272.25	Square feet
Kilograms	1,000	Grams		Square yards	0.0002066	Acres
Kilograms	2.205	Pounds		Square yards	9	Square feet
Kilometres	3,281	Feet		Square yards	1,296	Square inches
Kilometres	0.6214	Miles		Ton	1016.05	Kilograms
Litres	1,000	Cubic centmtrs		Ton	2,240	Pounds
Litres	0.0353	Cubic feet		Yards	3	Feet
Litres	61.02	Cubic inches		Yards	36	Inches
Litres	0.2642	Gallons		Yards	0.9144	Metres
Litres	1.057	Quarts (liquid)
Metres	100	Centimetres