API Gravity Calculator

Input Method:

Select Product:

1. What is API Gravity Calculator?

Definition: This calculator computes the API gravity of a liquid, a measure used primarily in the oil industry to indicate the density of a petroleum product relative to water.

Purpose: It helps classify crude oils and petroleum products, aiding in determining their quality, market value, and suitability for refining processes.

2. How Does the Calculator Work?

The calculator uses the following formulas:

\( \text{Specific Gravity (SG)} = \frac{\rho_{\text{Liquid}}}{\rho_{\text{water}}} \)
\( \text{API} = \frac{141.5}{\text{Specific Gravity}} - 131.5 \)

Where:

\( \rho_{\text{Liquid}} \): Density of the liquid (kg/m³);
\( \rho_{\text{water}} = 1000 \, \text{kg/m}^3 \): Density of water;
Density of the liquid is either selected from the dropdown or manually entered.

Steps:

Choose the input method: select a product from the dropdown or manually enter the liquid's density.
Calculate the specific gravity by dividing the liquid's density by the density of water (1000 kg/m³).
Compute the API gravity using the formula above.
Display the specific gravity and API gravity, formatted in scientific notation if the absolute value is less than 0.001, otherwise with 4 decimal places.

3. Importance of API Gravity Calculation

Calculating API gravity is crucial for:

Oil Classification: Higher API gravity indicates lighter oil, which is typically more valuable and easier to refine.
Market Valuation: API gravity affects the pricing of crude oil and petroleum products in the global market.
Refining Processes: Helps determine the appropriate refining techniques based on the oil's density.

4. Using the Calculator

Example 1 (Dropdown): Calculate the API gravity for Gasoline (Density = 760 kg/m³):

Input Method: Select from List;
Product: Gasoline;
Density of Gasoline = \( 760 \, \text{kg/m}^3 \);
Density of Water = \( 1000 \, \text{kg/m}^3 \);
Specific Gravity: \( \text{SG} = \frac{760}{1000} = 0.76 \);
API Gravity: \( \text{API} = \frac{141.5}{0.76} - 131.5 \approx 54.9342 \);
Result: \( \text{SG} = 0.7600 \), \( \text{API} = 54.9342 \).

Example 2 (Manual Input): Calculate the API gravity for a liquid with density = 950 kg/m³:

Input Method: Manual Input;
Density of Liquid = \( 950 \, \text{kg/m}^3 \);
Density of Water = \( 1000 \, \text{kg/m}^3 \);
Specific Gravity: \( \text{SG} = \frac{950}{1000} = 0.95 \);
API Gravity: \( \text{API} = \frac{141.5}{0.95} - 131.5 \approx 17.4211 \);
Result: \( \text{SG} = 0.9500 \), \( \text{API} = 17.4211 \).

5. Frequently Asked Questions (FAQ)

Q: What does a higher API gravity mean?
A: A higher API gravity indicates a lighter liquid, which is less dense than water and typically more valuable in the petroleum industry due to easier refining.

Q: Why is the density of water used in the calculation?
A: The specific gravity is a ratio of the liquid's density to the density of water (1000 kg/m³), which serves as a standard reference for comparing densities.

Q: Can this calculator be used for liquids other than petroleum products?
A: Yes, you can manually input the density of any liquid to calculate its API gravity, though the API scale is primarily used for petroleum products.