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API Gravity Formula:
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API Gravity is a measure of how heavy or light a petroleum liquid is compared to water. It was developed by the American Petroleum Institute to standardize measurements of petroleum density. Higher API gravity values indicate lighter (less dense) liquids.
The calculator uses the standard API gravity formula:
Where:
Temperature Correction: The calculator optionally applies temperature correction factors to adjust for measurements taken at non-standard temperatures.
Details: API gravity is crucial in the petroleum industry for classifying crude oils, determining product quality, and calculating shipping quantities. Lighter oils (higher API gravity) are generally more valuable as they yield more high-value products like gasoline.
Tips: Enter specific gravity (SG) as a dimensionless number (typically between 0.8-1.0 for most petroleum products). For more accurate results, include the measurement temperature to apply standard correction factors.
Q1: What's the relationship between API gravity and specific gravity?
A: API gravity is inversely related to specific gravity. As SG increases (liquid becomes denser), API gravity decreases.
Q2: What are typical API gravity values for crude oil?
A: Light crude: >31.1°API, Medium crude: 22.3-31.1°API, Heavy crude: <22.3°API, Extra heavy crude: <10°API.
Q3: Why is temperature correction important?
A: Petroleum products expand with temperature, affecting density. Measurements should be corrected to standard temperature (usually 60°F/15.6°C).
Q4: How does API gravity relate to product quality?
A: Higher API gravity crudes generally yield more valuable light products (gasoline, jet fuel) and require less processing.
Q5: Can this calculator be used for non-petroleum liquids?
A: The formula works for any liquid, but temperature correction factors are specific to petroleum products.