API Gravity

Typical API Table
API / SG Calculator

API (American Petroleum Institute) gravity is a dimensionless measure of the density of a petroleum liquid (e.g. oil) compared to water.

For an API gravity greater than 10, a petroleum liquid will float on water. Conversely, an API gravity less than 10, will cause petroleum liquid to sink in water.

As such, an oil with a low specific gravity will have a high API gravity.

Table of API values

API	Specific Gravity	Density (std condns)
API	Specific Gravity	lb/US gal	kg/m³
4	1.044	8.699	1042.4
5	1.037	8.636	1034.8
10	1.000	8.330	998.2
15	0.966	8.046	964.1
20	0.934	7.781	932.3
25	0.904	7.532	902.5
30	0.876	7.299	874.6
35	0.850	7.080	848.3
40	0.825	6.873	823.6
45	0.802	6.678	800.3
50	0.780	6.494	778.2

API / S.G. Converter

API -> S.G. Converter:
Formula:	$API = (\frac{141.5}{SG}) - 131.5$
S.G.:

Result:	units

S.G. -> API Converter:
Formula:	$SG = \frac{141.5}{(API + 131.5)}$
API Gravity:

Result:	units