Relative Permittivity - the Dielectric Constant

Common materials and their relative permittivity. The dielectric constant (relative permittivity) indicates how easily a material can become polarized by an electric field. Relative permittivity is calculated as εr = ε / ε₀, where ε is the permittivity of the substance and ε₀ is the permittivity of vacuum (8.854187817×10⁻¹² C²/(N m²)).

Material	Relative Permittivity (εr)
Acetaldehyde (41°F)	21.8
Acetic Acid (68°F)	6.2
Acetic Acid (36°F)	4.1
Acetone (77°F)	20.7
Acetone (127°F)	17.7
Acetone (32°F)	1.0159
Acetyl Acetone (68°F)	23.1
Acetyl Bromide (68°F)	16.5
Acetyl Chloride (68°F)	15.8
Acetyle Acetone (68°F)	25
Acetylene (32°F)	1.0217
Air (Dry) (68°F)	1.000536
Air, Liquid (-191 oC)	1.4
Alcohol, Industrial	16-31
Alumina	9.3-11.5
Aluminum Bromide (212°F)	3.4
Aluminum Fluoride	2.2
Amber	2.8-2.9
Ammonia (-74°F)	25
Ammonia (-30°F)	22
Ammonia (40°F)	18.9
Ammonia (69°F)	16.5
Aniline (32°F)	7.8
Aniline (68°F)	7.3
Aniline (212°F)	5.5
Araldite	3.6
Argon (68°F)	1.000513
Bakelite	3.5-5.0
Bakelite, mica filled	4.7
Benzene (68°F)	2.3
Body tissue	8
Butane (30°F)	1.4
Carbon dioxide (68°F)	1.000921
Carbon disulfide	2.6
Calcium	3
Casting compound	2.5
Caster oil	4.7
Cellulose acetat	3.3 - 3.9
Ceramic, MgNb2O6	21
Ceramic, ZnNb2O6	25
Ceramic, MgTa2O6	28
Ceramic, ZnTa2O6	38
Chlorine (32°F)	2
Chloroform (68°F)	4.8
Concrete	4.5
Diamond	5.5 - 10
Ebonite	2.5 - 2.9
Epoxy Resin (Cast)	3.6
Ethanol (25 oC, 77°F)	24.3
Ethyl Acetate (77°F)	6
Ethyl Alcohol (77°F)	24.3
Ethylene glycol	37
Formamide (20 oC)	84
Formica	4.6 - 4.9
Furfural	42
R12 Dichlorodifluoromethane (70°F)	2.4
Glass	3.7 - 10
Glass, Pyrex	4.8
Glycerin, Liquid	47-68
Glycerol (77°F)	42.5
Granite	7 - 9
Graphite	10 - 15
Guttapercha	4
Hard paper, laminated	4.5
Hydrazine (20 oC)	52
Hydrocyanic acid (21 oC)	2.3
Hydrofluoric acid (0 oC)	83.6
Hydrogen peroxide (25 oC)	60
Ice (-2 oC)	3.2
Isoprene (77°F)	2.1
Insulation of high voltage cables	4.2
Insulation of telephone cables	1.5
Marble	8
Methanol (20 oC)	33.6
Mica	2.5 - 7
Mineral Oil (80°F)	2.1
Mylar	3.1
Neoprene	6.7
Nitrogen (68°F)	1.00058
Nylon	4.0 - 5.0
Oil paper	4
Olive oil	3
Paper	2.3
Paper, impregnated	5
Paper, waxed	2.5
Paraffin oil	2.2
Paraffin Wax	2.1-2.5
Petroleum	2.2
Phenolic resin	8
Plexiglass	3.2
Polyester Resin	2.8 - 4.5
Polyethylene, XLPE	2.2-2.4
Polyamide	2.8
Polymide	3.4
Polypropylene	2.2
Polystyrene	3
Porcelain	5.0-7.0
Pressed board	4
Pyrex Glass	4.3 - 5.0
Quartz	4.5
Rubber	3
Salt	3.0 - 15.0
Sapphire	8.9 - 11.1
Shellac	3.5
Silica Sand	2.5-3.5
Silicon	11.0 - 12.0
Silicon dioxide	3.9
Silicon oil	2.2 - 2.8
Slate	4
Sodium chloride	5.6
Soft rubber	2.5
Steatite	6
Sulfur	3.5
Sulfuric acid (20 oC)	84
Polytetrafluoroethylene (PTFE)	2
Teflon, PTFE	2.1
Titanium dioxide	86 - 173
Transformer oil, mineral	2.2
Transformer oil, vegetable	2.5
Turpentine	2.2
Vacuum	1
Vulcanized fibres	2.5
Water	4 - 88
Wood, Dry	2 - 6