Specific Gravity Calculator

About the Specific Gravity Calculator

Calculates the specific gravity of a substance as the ratio of its density to the density of water (1000 kg/m³).

How to use this calculator

1. Enter the density of the substance in a consistent unit, such as \(\text{g/mL}\) or \(\text{kg/m}^3\).
2. Enter the density of water in the same unit.
3. Click calculate to get the specific gravity.
4. Check the result, a value greater than \(1\) means the substance is denser than water, and a value less than \(1\) means it is less dense than water.

The formula explained

Specific gravity is found by dividing the density of the substance by the density of water, so it tells you how dense the substance is relative to water. Because it is a ratio, specific gravity has no units.

• SG = specific gravity, a unitless ratio
• \(\rho_{substance}\) = density of the substance
• \(\rho_{water}\) = density of water

Step by step method

1. Write down the density of the substance and the density of water in the same units.
2. Substitute the values into \( SG = \frac{\rho_{substance}}{\rho_{water}} \).
3. Divide to find the ratio.
4. Interpret the result, since \( SG > 1 \) means denser than water and \( SG < 1 \) means less dense than water.

Worked example

Problem. A liquid has density \(0.92\\,\text{g/mL}\). Water has density \(1.00\\,\text{g/mL}\). Find the specific gravity.

1. Use \( SG = \frac{\rho_{substance}}{\rho_{water}} \).
2. Substitute the values, \( SG = \frac{0.92}{1.00} \).
3. Compute the ratio, \( SG = 0.92 \).

Tips and common mistakes

• Make sure both densities use the same units before dividing, otherwise the ratio will be wrong.
• Specific gravity does not have units, so do not write \(\text{g/mL}\) or \(\text{kg/m}^3\) in the final answer.

Frequently asked questions