The formula to calculate the API gravity is:
\[ API G = \frac{141.5}{SG} - 131.5 \]
Where:
API gravity is a scale used to measure the relative density of petroleum liquids with respect to temperature. The scale was developed by the American Petroleum Institute so that most petroleum fluids would fall between 10 and 70 API gravity, which helps simplify analysis.
Let's assume the following value:
Using the formula to calculate the API gravity:
\[ API G = \frac{141.5}{0.85} - 131.5 \approx 34.76 \]
The API gravity is approximately 34.76.