Specific Gravity of Liquid Calculator
Quickly determine the relative density of any liquid.
Result:
What is Specific Gravity?
Specific Gravity (SG), also known as relative density, is a dimensionless quantity that measures the ratio of the density of a substance to the density of a reference material. For liquids, the standard reference material is almost always pure water at its maximum density (which occurs at 4°C or 39.2°F).
Because it is a ratio of two densities with the same units, specific gravity has no units itself. It is a critical value in fields like chemistry, fluid mechanics, geology, and brewing to determine the concentration of solutions or the purity of a substance.
How to Calculate Specific Gravity
The formula for calculating specific gravity is straightforward:
SG = ρsubstance / ρreference
Where:
- ρsubstance: The density of the liquid being measured.
- ρreference: The density of the reference liquid (Water ≈ 1000 kg/m³ or 1 g/cm³).
Why Use a Specific Gravity Calculator?
Manual calculations are prone to unit conversion errors. Whether you are working in metric (kg/m³) or imperial (lb/ft³), this calculator ensures that your reference density matches your input density. It is an essential tool for engineers calculating buoyancy, winemakers tracking fermentation progress (Original Gravity vs. Final Gravity), and mechanics checking battery acid levels or engine coolant.
Frequently Asked Questions
What does a specific gravity greater than 1 mean?
If the SG is greater than 1.0, the liquid is denser than water and will sink. If the SG is less than 1.0, the liquid is less dense than water and will float.
Does temperature affect specific gravity?
Yes, significantly. Most liquids expand when heated, which decreases their density. Therefore, specific gravity measurements are usually tied to a specific temperature (e.g., 20°C).
Is relative density the same as specific gravity?
Yes, in most scientific contexts, the terms are used interchangeably, though "specific gravity" is more common in North American industrial applications.