1. What is API Gravity?

API gravity is a measure of how heavy or light a petroleum liquid is compared to water. The American Petroleum Institute (API) established this measurement scale to quantify the density of petroleum liquids.

2. How Does the Calculator Work?

The calculator uses the API gravity formula:

Where:

• \( API \) — API gravity in degrees
• \( SG \) — Specific gravity (dimensionless)

Explanation: The equation converts specific gravity (density relative to water) to the API gravity scale. Higher API values indicate lighter (less dense) liquids.

3. Importance of API Gravity

Details: API gravity is crucial in the petroleum industry for classifying crude oils, determining product quality, and calculating shipping quantities. It affects refining processes and product values.

4. Using the Calculator

Tips: Enter specific gravity (measured at 60°F or corrected to 60°F) and temperature. The calculator will determine the API gravity at the standard reference temperature.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between API gravity and specific gravity?
A: API gravity is an inverse scale that increases as density decreases, while specific gravity is a direct density measurement relative to water.

Q2: What are typical API gravity values for crude oil?
A: Light crudes: >31.1°API, Medium crudes: 22.3-31.1°API, Heavy crudes: <22.3°API, Extra heavy: <10°API.

Q3: Why is temperature important in API gravity measurements?
A: Density changes with temperature, so measurements must be temperature-corrected to the standard 60°F reference.

Q4: How does API gravity affect oil prices?
A: Lighter crudes (higher API) typically command higher prices as they yield more valuable products like gasoline.

Q5: Can this calculator be used for other liquids?
A: The API scale is specifically designed for petroleum products. Other industries use different density measurements.