Resistivity and Conductivity  Temperature Coefficients Common Materials
Resistivity, conductivity and temperature coefficients for common materials like silver, gold, platinum, iron and more..
Resistivity is
 the electrical resistance of a unit cube of a material measured between the opposite faces of the cube
Electric Conductor Resistance Calculator
This calculator can be used to calculate electrical resistance of a conductor.
Material  Resistivity Coefficient ^{2) } ρ  (ohm m^{2}/m) (Ω m)  Temperature Coefficient ^{2) α } (per degree C) (1/^{o}C)  Conductivity  σ  (1 /(Ω m)) 

Aluminum  2.65 x 10^{8}  3.8 x 10^{3}  3.77 x 10^{7} 
Aluminum alloy 3003, rolled  3.7 x 10^{8}  
Aluminum alloy 2014, annealed  3.4 x 10^{8}  
Aluminum alloy 360  7.5 x 10^{8}  
Aluminum bronze  12 x 10^{8}  
Animal fat  14 x 10^{2}  
Animal muscle  0.35  
Antimony  41.8 x 10^{8}  
Barium (0^{o}C)  30.2 x 10^{8}  
Beryllium  4.0 x 10^{8}  
Beryllium copper 25  7 x 10^{8}  
Bismuth  115 x 10^{8}  
Brass  58% Cu  5.9 x 10^{8}  1.5 x 10^{3}  
Brass  63% Cu  7.1 x 10^{8}  1.5 x 10^{3}  
Cadmium  7.4 x 10^{8}  
Caesium (0^{o}C)  18.8 x 10^{8}  
Calcium (0^{o}C)  3.11 x 10^{8}  
Carbon (graphite)^{1)}  3  60 x 10^{5}  4.8 x 10^{4}  
Cast iron  100 x 10^{8}  
Cerium (0^{o}C)  73 x 10^{8}  
Chromel (alloy of chromium and aluminum)  0.58 x 10^{3}  
Chromium  13 x 10^{8}  
Cobalt  9 x 10^{8}  
Constantan  49 x 10^{8}  3 x 10^{5}  0.20 x 10^{7} 
Copper  1.724 x 10^{8}  4.29 x 10^{3}  5.95 x 10^{7} 
Cupronickel 5545 (constantan)  43 x 10^{8}  
Dysprosium (0^{o}C)  89 x 10^{8}  
Erbium (0^{o}C)  81 x 10^{8}  
Eureka  0.1 x 10^{3}  
Europium (0^{o}C)  89 x 10^{8}  
Gadolium  126 x 10^{8}  
Gallium (1.1K)  13.6 x 10^{8}  
Germanium^{1)}  1  500 x 10^{3}  50 x 10^{3}  
Glass  1  10000 x 10^{9}  10^{12}  
Gold  2.24 x 10^{8}  
Graphite  800 x 10^{8}  2.0 x 10^{4}  
Hafnium (0.35K)  30.4 x 10^{8}  
Hastelloy C  125 x 10^{8}  
Holmium (0^{o}C)  90 x 10^{8}  
Indium (3.35K)  8 x 10^{8}  
Inconel  103 x 10^{8}  
Iridium  5.3 x 10^{8}  
Iron  9.71 x 10^{8}  6.41 x 10^{3}  1.03 x 10^{7} 
Lanthanum (4.71K)  54 x 10^{8}  
Lead  20.6 x 10^{8}  0.45 x 10^{7}  
Lithium  9.28 x 10^{8}  
Lutetium  54 x 10^{8}  
Magnesium  4.45 x 10^{8}  
Magnesium alloy AZ31B  9 x 10^{8}  
Manganese  185 x 10^{8}  1.0 x 10^{5}  
Mercury  98.4 x 10^{8}  8.9 x 10^{3}  0.10 x 10^{7} 
Mica (Glimmer)  1 x 10^{13}  
Mild steel  15 x 10^{8}  6.6 x 10^{3}  
Molybdenum  5.2 x 10^{8}  
Monel  58 x 10^{8}  
Neodymium  61 x 10^{8}  
Nichrome (alloy of nickel and chromium)  100  150 x 10^{8}  0.40 x 10^{3}  
Nickel  6.85 x 10^{8}  6.41 x 10^{3}  
Nickeline  50 x 10^{8}  2.3 x 10^{4}  
Niobium (Columbium)  13 x 10^{8}  
Osmium  9 x 10^{8}  
Palladium  10.5 x 10^{8}  
Phosphorus  1 x 10^{12}  
Platinum  10.5 x 10^{8}  3.93 x 10^{3}  0.943 x 10^{7} 
Plutonium  141.4 x 10^{8}  
Polonium  40 x 10^{8}  
Potassium  7.01 x 10^{8}  
Praseodymium  65 x 10^{8}  
Promethium  50 x 10^{8}  
Protactinium (1.4K)  17.7 x 10^{8}  
Quartz (fused)  7.5 x 10^{17}  
Rhenium (1.7K)  17.2 x 10^{8}  
Rhodium  4.6 x 10^{8}  
Rubber  hard  1  100 x 10^{13}  
Rubidium  11.5 x 10^{8}  
Ruthenium (0.49K)  11.5 x 10^{8}  
Samarium  91.4 x 10^{8}  
Scandium  50.5 x 10^{8}  
Selenium  12.0 x 10^{8}  
Silicon^{1)}  0.160  70 x 10^{3}  
Silver  1.59 x 10^{8}  6.1 x 10^{3}  6.29 x 10^{7} 
Sodium  4.2 x 10^{8}  
Soil, typical ground  10^{2}  10^{4}  
Solder  15 x 10^{8}  
Stainless steel  10^{6}  
Strontium  12.3 x 10^{8}  
Sulfur  1 x 10^{17}  
Tantalum  12.4 x 10^{8}  
Terbium  113 x 10^{8}  
Thallium (2.37K)  15 x 10^{8}  
Thorium  18 x 10^{8}  
Thulium  67 x 10^{8}  
Tin  11.0 x 10^{8}  4.2 x 10^{3}  
Titanium  43 x 10^{8}  
Tungsten  5.65 x 10^{8}  4.5 x 10^{3}  1.79 x 10^{7} 
Uranium  30 x 10^{8}  
Vanadium  25 x 10^{8}  
Water, distilled  10^{4}  
Water, fresh  10^{2}  
Water, salt  4  
Ytterbium  27.7 x 10^{8}  
Yttrium  55 x 10^{8}  
Zinc  5.92 x 10^{8}  3.7 x 10^{3}  
Zirconium (0.55K)  38.8 x 10^{8} 
^{1)} Note!  the resistivity depends strongly on the presence of impurities in the material.
^{2}^{)} Note!  the resistivity depends strongly on the temperature of the material. The table above is based on 20^{o}C reference.
Convert between Electrical Resistivity Units
 1 Ω m = 10^{2} Ω cm = 2.54 10^{2} Ω inch = 3.048 10^{1} Ω foot
Electrical Resistance in a Wire
The electrical resistance of a wire is greater for a longer wire and less for a wire of larger cross sectional area. The resistance depend on the material of which it is made and can be expressed as:
R = ρ L / A (1)
where
R = resistance (ohm, Ω)
ρ = resistivity coefficient (ohm m, Ω m)
L = length of wire (m)
A = cross sectional area of wire (m^{2})
The factor in the resistance which takes into account the nature of the material is the resistivity. Since it is temperature dependent, it can be used to calculate the resistance of a wire of given geometry at different temperatures.
The inverse of resistivity is called conductivity and can be expressed as:
σ = 1 / ρ (2)
where
σ = conductivity (1 / Ω m)
Example  Resistance in an Aluminum Wire
Resistance of an aluminum cable with length 10 m and cross sectional area of 3 mm^{2} can be calculated as
R = (2.65 10^{8} Ω m) (10 m) / ((3 mm^{2}) (10^{6} m^{2}/mm^{2}))
= 0.09 Ω
Resistance
The electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current which flows through it:
R = U / I (3)
where
R = resistance (ohm)
U = voltage (V)
I = current (A)
Ohm's Law
If the resistance is constant over a considerable range of voltage, then Ohm's law,
I = U / R (4)
can be used to predict the behavior of the material.
Resistivity vs. Temperature
Change in resistivity vs. temperature can be calculated as
dρ = ρ α dt (5)
where
dρ = change in resistivity (ohm m^{2}/m)
α = temperature coefficient (1/^{o}C)
dt = change in temperature (^{o}C)
Example  Change in Resistivity
Aluminum with resistivity 2.65 x 10^{8} ohm m^{2}/m is heated from 20 ^{o}C to 100 ^{o}C. The temperature coefficient for aluminum is 3.8 x 10^{3} 1/^{o}C. The change in resistivity can be calculated as
dρ = (2.65 10^{8} ohm m^{2}/m) (3.8 10^{3} 1/^{o}C) ((100 ^{o}C)  (20 ^{o}C))
= 0.8 10^{8} ohm m^{2}/m
The final resistivity can be calculated as
ρ = (2.65 10^{8} ohm m^{2}/m) + (0.8 10^{8} ohm m^{2}/m)
= 3.45 10^{8} ohm m^{2}/m
Resistivity Coefficient vs. Temperature Calculator
This caculator can be used to calculate resistivity in a conductor material vs. temperature.
Resistance and Temperature
For most materials the electrical resistance increases with temperature. Change in resistance can be expressed as
dR / R_{s} = α dT (6)
where
dR = change in resistance (ohm)
R_{s} = standard resistance according reference tables (ohm)
α = temperature coefficient of resistance (^{o}C^{1})
dT = change in temperature from reference temperature (^{o}C, K)
(5) can be modified to:
dR = α dT R_{s} (6b)
The "temperature coefficient of resistance"  α  of a material is the increase in the resistance of a 1 Ω resistor of that material when the temperature is increased 1 ^{o}C.
Example  Resistance of a Copper Wire in Hot Weather
A copper wire with resistance 0.5 kΩ at normal operating temperature 20^{o}C is in hot sunny weather heated to 80 ^{o}C. The temperature coefficient for copper is 4.29 x 10^{3} (1/^{o}C) and the change in resistance can be calculated as
dR = (4.29 x 10^{3} 1/^{o}C) ((80 ^{o}C)  (20 ^{o}C)) (0.5 kΩ)
= 0.13 (kΩ)
The resulting resistance for the copper wire in hot weather will be
R = (0.5 kΩ) + (0.13 kΩ)
= 0.63 (kΩ)
= 630 (Ω)
Example  Resistance of a Carbon Resistor when Temperature is changed
A carbon resistor with resistance 1 kΩ at temperature 20^{o}C is heated to 120 ^{o}C. The temperature coefficient for carbon is negative 4.8 x 10^{4} (1/^{o}C)  the resistance is reduced with increasing temperature.
The change in resistance can be calculated as
dR = (4.8 x 10^{4} 1/^{o}C) ((120 ^{o}C)  (20 ^{o}C)) (1 kΩ)
=  0.048 (kΩ)
The resulting resistance for the resistor will be
R = (1 kΩ)  (0.048 kΩ)
= 0.952 (kΩ)
= 952 (Ω)
Resistance vs. Temperature Calculator
This caculator can be used to calculate resistance in a conductor vs. temperature.
Temperature Correction Factors for Conductor Resistance
Temperature of Conductor (°C)  Factor to Convert to 20°C  Reciprocal to Convert from 20°C 

5  1.064  0.940 
6  1.059  0.944 
7  1.055  0.948 
8  1.050  0.952 
9  1.046  0.956 
10  1.042  0.960 
11  1.037  0.964 
12  1.033  0.968 
13  1.029  0.972 
14  1.025  0.976 
15  1.020  0.980 
16  1.016  0.984 
17  1.012  0.988 
18  1.008  0.992 
19  1.004  0.996 
20  1.000  1.000 
21  0.996  1.004 
22  0.992  1.008 
23  0.988  1.012 
24  0.984  1.016 
25  0.980  1.020 
26  0.977  1.024 
27  0.973  1.028 
28  0.969  1.032 
29  0.965  1.036 
30  0.962  1.040 
31  0.958  1.044 
32  0.954  1.048 
33  0.951  1.052 
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