Specific gravity (SG), also known as relative density, is a dimensionless quantity that represents the ratio of the density of a substance to the density of a reference substance, typically water for liquids and solids, and air for gases.
The formula is:
For liquids and solids, the reference substance is usually water at 4 ℃, which has a density of 1 g/cm3. For gases, the reference substance is typically dry air at standard temperature and pressure (STP).
Understanding specific gravity is crucial in various scientific and industrial applications, ranging from material science to fluid mechanics. Alfa Chemistry provides the following specific gravity table of some liquids, gases, and solids for your review.
Specific Gravity of Liquids
Liquids exhibit varying specific gravities depending on their chemical composition and temperature.
| Liquids and Fluids | Temperature | Specific Gravity |
| 1-Propanol | 20℃ | 0.805 |
| 2-Propanol | 20℃ | 0.786 |
| Acetic Acid | 25℃ | 1.052 |
| Acetone | 25℃ | 0.787 |
| Acetylene, liquid | -121℉ | 0.62 |
| 70℉ | 0.38 | |
| Alcohol, ethyl (Ethanol) | 25℃ | 0.787 |
| Alcohol, methyl (methanol) | 25℃ | 0.791 |
| Alcohol, propyl | 25 °C | 0.743 |
| Acetonitrile | 20 °C | 0.722 |
| Beer | 25℃ | 1.01 |
| Benzene | 25℃ | 0.876 |
| Benzil | 25℃ | 1.054 |
| Butane, liquid | 25℃ | 0.601 |
| Butylamine | 20℃ | 0.742 |
| Caproic acid | 25℃ | 0.924 |
| Carbolic acid | 15℃ | 0.959 |
| Cyclohexane | 20 °C | 0.718 |
| Cyclopentane | 20 °C | 0.686 |
| 1,4-Dioxane | 20 °C | 1.005 |
| Dichloromethane | 20 °C | 1.315 |
| Carbon disulfide | 25℃ | 1.265 |
| Carbon tetrachloride | 25℃ | 1.589 |
| Chloride | 25℃ | 1.56 |
| 60℉ | 1.42 | |
| Chlorodifluoromethane refrigerant R22 | 25℃ | 1.197 |
| Citric acid | 25℃ | 1.665 |
| Coconut Oil | 15℃ | 0.925 |
| Crude oil, California | 60℉ | 0.918 |
| Diethyl ether | 20 °C | 0.656 |
| Diethylene glycol | 15 °C | 1.098 |
| Dimethyl Acetamide | 20 °C | 0.904 |
| Dimethyl Sulfoxide | 20 °C | 1.077 |
| Dodecane | 25 °C | 0.695 |
| Decane | 25℃ | 0.728 |
| Ethane | -89℃ | 0.572 |
| Ethanol | 20℃ | 0.789 |
| Ether (Diethyl ether) | 25℃ | 0.716 |
| Ethyl acetate | 20℃ | 0.901 |
| Ethylamine | 16℃ | 0.683 |
| Ethylene glycol | 25℃ | 1.1 |
| Formaldehyde | 45℃ | 0.815 |
| Fuel oil | 60℉ | 0.893 |
| Gasoline, natural | 60℉ | 0.713 |
| Gasoline, Vehicle | 60℉ | 0.739 |
| Glycol | 25℃ | 1.11 |
| Heptane | 25℃ | 0.681 |
| Linseed Oil | 25℃ | 0.932 |
| m-Xylene | 20℃ | 0.864 |
| 1,1,2-Trichlorotrifluoroethane | 25 °C | 1.558 |
| 1,2,4-Trichlorobenzene | 20 °C | 1.444 |
| 2-Methoxyethanol | 20 °C | 0.93 |
| Mercury | 25℃ | 13.633 |
| Methane | -164℃ | 0.466 |
| Methanol | 20℃ | 0.791 |
| Methyl acetate | 20℃ | 0.935 |
| Milk | 1.035 | |
| Naphtha, Petroleum Naphtha | 15℃ | 0.667 |
| Nonanol | 25℃ | 0.823 |
| o-Xylene | 20℃ | 0.88 |
| Octane | 25℃ | 0.701 |
| Oil, Castor | 25℃ | 0.959 |
| Olive Oil | 15℃ | 0.915 |
| Oxygen | –182.96 ℃ | 1.14 |
| p-Xylene | 20℃ | 0.861 |
| Palm Oil | 15.5℃ | 0.923 |
| Palmitic Acid | 25℃ | 0.853 |
| Propane | 40℃ | 0.585 |
| 25℃ | 0.495 | |
| Propyl acetate | 20℃ | 0.889 |
| Sea water | 25℃ | 1.028 |
| 77℉ | 1.025 | |
| Trichlorofluoromethane refrigerant R11 | 25℃ | 1.48 |
| Turpentine | 25℃ | 0.871 |
| Water, pure | 39.2℉ (4℃) | 1 |
Specific Gravity of Gases
Gases have much lower densities compared to liquids and solids, and their specific gravity is calculated relative to air.
| Gases | Specific Gravity |
| Acetylene (ethyne) | 0.899 |
| Air | 1 |
| Alcohol vapor | 1.601 |
| Ammonia | 0.59 |
| Argon | 1.38 |
| Benzene | 2.6969 |
| Blast Furnace gas | 1.02 |
| Carbon dioxide | 1.5189 |
| Chlorine | 2.486 |
| Coke Oven Gas | 0.44 |
| n-Decane | 4.9125 |
| Deutrium | 0.07 |
| Ethane | 1.049 |
| Ether vapor | 2.586 |
| Ethylbenzene | 3.6655 |
| Ethylene (Ethene) | 0.9686 |
| 3-Ethylpentane | 3.4596 |
| Fluorine | 1.31 |
| Helium | 0.138 |
| Hydrogen | 0.0696 |
| Hydrogen chloride | 1.268 |
| Hydrogen sulfide | 1.1763 |
| Hydrofluoric acid | 2.37 |
| Isobutene | 1.9372 |
| Isooctane | 3.9439 |
| Krypton | 2.89 |
| Marsh gas | 0.555 |
| Mercury vapor | 6.94 |
| Methane | 0.5537 |
| Natural Gas (typical) | 0.60 - 0.70 |
| Neon | 0.697 |
| Nitric oxide | 1.037 |
| Nitrogen (pure) | 0.9669 |
| Nitrogen (atmospheric) | 0.9723 |
| Oxygen | 1.1044 |
| Ozone | 1.66 |
| Sulfur Dioxide | 2.264 |
| Water vapor | 0.6218 |
| Xenon | 4.53 |
Specific Gravity of Solids
Solids can have a wide range of specific gravities, influenced by their molecular structure and composition.
| Solids and Metals | Specific Gravity |
| ABS, extrusion grade | 1.05 |
| Acrylic | 1.19 |
| Alumina | 3.4 |
| Antimony | 6.69 |
| Asphalt | 1.1 |
| Bark | 0.25 |
| Barite | 4.5 |
| Barium | 3.62 |
| Beryllium | 1.848 |
| Bismuth | 9.79 |
| Boron | 2.32 |
| Brass, cast rolled | 8.4 - 8.7 |
| Brick, common red | 1.75 |
| Brick, fire clay (firebrick) | 2.4 |
| Calcium | 4.58 |
| Carbon, solid | 2.1 |
| Carbon, powdered | 0.08 |
| Cement | 1.2 - 1.5 |
| Cerium | 6.77 |
| Chalk | 2.3 |
| Charcoal, wood | 0.4 |
| Chromium | 7.19 |
| Cobalt | 8.71 |
| Copper | 8.89 |
| Diamond | 3.51 |
| Earth, dry | 1.4 |
| Epoxy | 1.8 |
| Europium | 5.244 |
| Ferrosilicon 15% | 6.7 - 7.1 |
| Gallium | 5.91 |
| Glass min. | 2.4 |
| Glass max. | 2.8 |
| Gold, pure | 19.32 |
| Graphite | 2.07 |
| Hafnium | 13.31 |
| Ice (0℃, 32℉) | 0.92 |
| Indium | 7.31 |
| Iodine | 4.93 |
| Iron cast min. | 7.03 |
| Iron cast max. | 7.13 |
| Lead | 11.35 |
| Leather | 0.95 |
| Limestone | 2.6 |
| Lithium | 0.53 |
| Magnesite | 3 |
| Manganese | 7.21 - 7.44 |
| Magnesium | 1.738 |
| Mercury | 13.534 |
| Molybdenum | 10.22 |
| Neodymium | 7 |
| Nickel | 8.9 |
| Nylon 6 Cast | 1.16 |
| Paper | 0.9 |
| Palladium | 12.02 |
| Phosphorus | 1.8 |
| Plaster, light | 0.7 |
| Platinum | 21.45 |
| Porcelain | 2.5 |
| Polytetrafluoroethylene (PTFE) | 2.19 |
| PVC | 1.39 |
| Rhenium | 21.02 |
| Silicon | 2.33 |
| Silicon carbide | 3.1 |
| Silicon nitride | 3.2 |
| Tile | 1.8 |
| Tin | 7.31 |
| Tungsten | 19.22 |
| Tungsten carbide | 14.29 |
| Wood, oak | 0.7 |
| Zinc, cast rolled | 6.9 - 7.2 |
| Zirconium | 6.506 |
Applications of Specific Gravity
- Quality Control: In manufacturing, specific gravity measurements ensure the consistency and quality of products, such as in the production of beverages, chemicals, and building materials.
- Geology and Mineralogy: Specific gravity helps identify minerals and determine their purity.
- Medicine: In clinical settings, the specific gravity of urine can indicate hydration levels and help diagnose various conditions.
Measuring Specific Gravity
Specific gravity can be measured using various instruments:
- Hydrometer: A simple device that floats in the liquid, with its buoyancy indicating the specific gravity.
- Pycnometer: A precise laboratory instrument used for measuring the specific gravity of liquids and fine powders.
- Digital Density Meters: Modern devices that provide highly accurate measurements using oscillating U-tube technology.
