Specific Gravity Calculator – Accurate Density Measurements

You pick up a rock, a piece of metal, or even a gemstone, and you wonder — is this real, and what exactly is its density? In science, engineering, and even jewellery, one quick way to answer that is by measuring specific gravity (SG). Instead of memorising tables or running long formulas, a Specific Gravity Calculator does the work for you. Just provide the weight of your sample in air and its weight in water, and the calculator gives you the exact SG — a direct measure of how dense it is compared to water.

Why Specific Gravity Matters

Specific gravity is important because it tells us how heavy a material is relative to water.

• In geology: Helps identify minerals and gemstones.
  
• In engineering: Determines if materials meet density requirements.
  
• In quality control: Checks if metals, plastics, or ceramics are pure.
  
• In everyday science: Even batteries are rated by the SG of their electrolytes.
  

Knowing SG is often quicker and easier than measuring full density directly.

What the Calculator Needs

When you open the calculator, you’ll see two inputs:

• Weight in Air (g): The dry weight of your object on a balance.
  
• Weight in Water (g): The weight of the same object when fully submerged in water.
  

These two values are all you need — because the difference between them equals the buoyant force, which links directly to volume.

How the Calculator Works Step by Step

1. Enter weight in air. Place your sample on a balance and note the mass.
   
2. Measure weight in water. Suspend the sample fully in water without touching the sides or bottom. Record the reading.
   
3. Calculator applies formula. It subtracts the two weights, finds the buoyant force, and divides.
   
4. Output appears instantly. You get the SG value, usually to 2–3 decimal places.
   
5. Interpret result. Compare with standard tables of minerals, metals, or solutions to identify the material.