1. What is API Gravity?

API Gravity is a measure of how heavy or light petroleum liquid is compared to water. It was developed by the American Petroleum Institute to standardize measurements of petroleum density.

2. How Does the Calculator Work?

The calculator uses the API Gravity formula:

Where:

• \( API \) — API Gravity (degrees)
• \( SG \) — Specific Gravity (dimensionless at 60°F)

Explanation: The equation converts specific gravity (relative density) to the API Gravity scale where water has an API gravity of 10.

3. Importance of API Gravity

Details: API Gravity is crucial in the petroleum industry for classifying crude oils. Higher API gravity indicates lighter (less dense) crude oil, while lower values indicate heavier crude oil.

4. Using the Calculator

Tips: Enter specific gravity measured at 60°F (15.6°C). The value must be greater than 0. Typical crude oils range from 10-50° API.

5. Frequently Asked Questions (FAQ)

Q1: What's the relationship between API and density?
A: API is inversely related to specific gravity - higher API means less dense oil. Crude with API > 31.1° is "light", < 22.3° is "heavy".

Q2: Why is API important in oil trading?
A: Lighter crude (higher API) typically commands higher prices as it yields more valuable products like gasoline with less processing.

Q3: What's the API gravity of water?
A: Water has an API gravity of exactly 10° (SG = 1.0 at 60°F).

Q4: What are typical API values for common oils?
A: Gasoline ~60°, Diesel ~35°, Light crude ~35-45°, Heavy crude ~10-30°, Bitumen <10°.

Q5: How does temperature affect API measurement?
A: API is standardized at 60°F. Measurements at other temperatures must be corrected to 60°F for accurate API calculation.