ABSTRACT
Area
Multiply By To obtain
Square millimeters 0.00155 1 × 10-6 0.01 1.2732
square inches (U.S.) square meters square centimeters circular millimeters
Square centimeters 1.196 × 10−4 0.00108 0.15500 1 × 10−4 100
square yards square feet square inches square meters square millimeters
Square kilometers 0.38610 1.1960 × 106 1.0764 × 107 1 × 106 247.10
square miles (U.S.) square yards square feet square meters acres (U.S.)
Square inches (U.S.) 0.00694 0.00077 6.4516 × 10−4 6.4516 645.15
square feet square yards square meters square centimeters square millimeters
Square feet (U.S.) 3.5870 × 10−8 0.11111 144 0.09290 929.03 2.2957 × 10−5
square miles square yards square inches square meters square centimeters acres
Square miles 640 3.0967 × 106 2.7878 × 107 2.5900
acres square yards square feet square kilometers
16.018 0.016018 1 1 0.001 0.062428 1 000 1 62.428 2 015.9 2.0159 125.85
Enthalpy, Heat of Vaporization, Heat of Conversion, Specic Energies
kJ/kg (J/g) cal/g Btu/lb
2.3244 0.55556 1 1 0.23901 0.43022 4.1840 1 1.8
Length
Multiply By To Obtain
Angstroms 1 × 10-10 3.9370 × 10-9 1 × 10-4 1 × 10-8 0.1
meters inches (U.S.) micrometers centimeters nanometers
Nanometers 1 × 10-9 1 × 10-7 10
meters centimeters angstroms
Micrometers (μm) 3.9370 × 10-5 1 × 10-6 1 × 10-4 1 × 104
inches (U.S.) meters centimeters angstroms
Millimeters 0.03937 1000
inches (U.S.) micrometers
Centimeters 0.39370 1 × 104 1 × 107 1 × 108
inches (U.S.) micrometers (μm) nanometers angstroms
Meters 6.2137 × 10-4 1.0936 39.370 1 × 109 1 × 1010
miles (statute) yards (U.S.) inches (U.S.) millimicrons angstroms
Kilometers 0.53961 0.62137 1093.6 3280.8
miles (nautical) miles (statute) yards feet
Inches (U.S.) 0.02778 2.5400 2.5400 × 108
yards centimeters angstroms
Feet (U.S.) 0.30480 30.480
meters centimeters
Yards (U.S.) 5.6818 × 10-4 0.91440 91.440
miles meters centimeters
Miles (nautical) 1.1516 2026.8 1.8533
statute miles yards kilometers
Miles (U.S. statute) 320 0.86836
rods nautical miles
MPa atm Torr (mm Hg) bar lbs/in2 (psi)
6.8948 × 10−3 0.068046 51.715 6.8948 × 10−2 1
1 9.8692 7500.6 10.0 145.04
0.101325 1 760.0 1.01325 14.696
1.3332 × 10−4 1.3158 × 10−3 1 1.332 × 10−3 0.019337
0.1 0.98692 750.06 1 14.504
Specic Heat, Entropy
kAJ/(kg.K) J/(g-K) Btu/(°R-lb)
4.184 1
1 0.23901
Specic Volume
m3/kg (L/g) cm3/g ft3/lb
0.062428 62.428 1
1 1000 16.018
0.001 1 0.016018
Speed of Sound
m/s ft/s
0.3048 1
1 3.2808
Surface Tension
N/m dyne/cm lb/in
175.13 175.13 × 103 1
1 1 000 5.7102 × 10-6
0.001 1 5.7102 × 10-3
Temperature
T(rankine) = 1.8T(kelvin)
T(celsius) = T(kelvin) – 273.15
T(fahrenheit) = T(rankine) – 459.67
T(fahrenheit) = 1.8T(celsius) + 32
Thermal Conductivity
mW/(cm-K) J/(s-cm-K) cal/(s-cm-K) Btu/(ft-hr-°R)
17.296 0.017296 0.0041338 1
1 0.001 2.3901 × 10-4 0.057816
Multiply By To Obtain
Feet per minute 0.01136 0.01829 0.5080 0.01667
miles per hour kilometers per hour centimeters per second feet per second
Feet per second 0.6818 1.097
30.48 0.3048 0.5921
miles per hour kilometers per hour centimeters per second meters per second knots
Knots (Br) 1.0 1.6889 1.1515 1.8532 0.5148
nautical miles per hour feet per second miles per hour kilometers per hour meters per second
Meters per second 3.281 2.237 3.600
feet per second miles per hour kilometers per hour
Miles per hour 1.467 0.4470 1.609 0.8684
Feet per second meters per second kilometers per hour knots
Viscosity
kg/(m-s) (N-s/m2, Pa⋅s) cP (10-2g/(cm-s)) lb-s/ft2 (slug/(ft-s)) lb/(ft-s)
1.48816 1 488.16 0.31081 1
1 1 000 0.020885 0.67197
0.001 1 2.0885 – 10-5 6.7197 – 10-4
47.881 4.7881 × 10-4 1 32.175
Multiply By To Obtain
Barrels (pet) 42 34.97
gallons (U.S.) gallons (Br.)
Cubic centimeters 10-3 0.0610
liters cubic inches
Cubic feet 28317 1728
0.03704 7.481
28.317
cubic centimeters cubic inches cubic yards gallons (U.S., liq.) liters
Cubic inches 16.387 0.016387 4.329 × 10-3 0.01732
cubic centimeters liters gallons (U.S., liq.) quarts (U.S., liq.)
Gallons, imperial 277.4 1.201 4.546
cubic inches U.S. gallons liters
Gallons, (U.S., liquid) 231 0.1337 3.785 0.8327
cubic inches cubic feet liters imperial gallons uid ounces (U.S.)
Ounces, uid 29.57 1.805
cubic centimeters cubic inches
Liters 0.2642 0.0353 1.0567
61.025
gallons cubic feet quarts (U.S., liq.) cubic inches
Quarts, (U.S., liquid) 0.0334 57.749 0.9463
cubic feet cubic inches liters
Multiply By To Obtain
Milligrams 2.2046 × 10-6 3.5274 × 10-5 0.01543
1 × 10-6
pounds (avoirdupois) ounces (avoirdupois) grains kilograms
Micrograms 1 × 10-6 grams
Grams 0.00220 0.03527
15.432 1 × 106
pounds (avoirdupois) ounces (avoirdupois) grains micrograms
Kilograms 0.00110 2.2046
35.274 1.5432 × 104
tons (short) pounds (avoirdupois) ounces (avoirdupois) grains
Grains 1.4286 × 10-4 0.00229 0.06480
64.799
pounds (avoirdupois) ounces (avoirdupois) grams milligrams
Ounces (avoirdupois) 3.1250 × 10-5 0.06250
437.50 28.350
tons (short) pounds (avoirdupois) grains grams
Pounds (avoirdupois) 5 × 10-4 16
7000 0.45359
453.59
tons (short) ounces (avoirdupois) grains kilograms grams
Tons (short, U.S.) 2000 3.200 × 104
907.19
pounds (avoirdupois) ounces (avoirdupois) kilograms
Tons (long) 2240 1016
pounds (avoirdupois) kilograms
Tons (metric) 1000 2205
1.102
kilograms pounds (avoirdupois) tons (short)
Because the mass of one liter of water is approximately one kg, mg/liter units of aqueous solution are nearly equal to ppm units. The precise equivalence is obtained by dividing by the density ρ:
ppm = (mg/liter)/ρ,
where the solution density, ρ, is in grams/cm3. Some sources will substitute specific gravity for density in the above equation. The specific gravity is the ratio of the solution density to that of the density of pure water at 4 °C. Since the density of pure water at 4 °C is 1 gram/cm3, the specific gravity is equal to the solution density when expressed in metric units of g/cm3.
