Physique
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Specific Gravity Calculator.
Calculate specific gravity from sample and reference densities.
Saisissez vos valeurs
Les résultats se mettent à jour pendant la saisie.
Results update automatically as you type.
Use Cases
Material Identification
Compare the density of an unknown material to a known reference to help identify it or verify its purity.
Example: A sample density of 2700 kg/m³ with water reference gives SG 2.7, typical for aluminum.
Quality Control in Manufacturing
Ensure consistency in products by checking that specific gravity falls within expected ranges, indicating proper composition.
Example: Checking a plastic batch with SG 0.92 against water reference to confirm it's polypropylene.
Frequently Asked Questions
- What is specific gravity?
- Specific gravity is the ratio of a substance's density to a reference density. It is dimensionless and indicates whether a substance will float or sink in the reference material. For liquids and solids, the reference is usually water at 4°C (1000 kg/m³).
- How do I use this calculator?
- Enter the sample density in kg/m³ and the reference density in kg/m³. The calculator divides the sample density by the reference density to give the specific gravity. Ensure both densities are in the same units (kg/m³) for accurate results.
- What does a specific gravity greater than 1 mean?
- If the specific gravity is greater than 1, the sample is denser than the reference and will sink in it. If less than 1, it is less dense and will float. A value of 1 means equal densities.
Tips & Common Mistakes
Tips
- Always use the same units for both densities; the calculator expects kg/m³.
- For most solids and liquids, use water at 4°C (1000 kg/m³) as the reference density.
- Specific gravity is temperature-dependent; note the temperature of your measurements for precise work.
- If you know the specific gravity and one density, you can rearrange the formula to find the other.
Common Mistakes to Avoid
- Using different units for sample and reference densities, leading to incorrect ratios.
- Forgetting that specific gravity is dimensionless and not a density itself.
- Assuming the reference density is always water; it can be any fluid depending on the application.
Last updated: August 13, 2026