Specific Gravity & Density Converter
Enter any one density value and instantly get all others. Bidirectional conversion between 8 common units.
Quick Presets
Density Converter
Click any field and type a value. All other fields update instantly.
Note on API Gravity: API = 141.5 / SG - 131.5. Only valid for liquids. Water = 10 API. Lighter fluids have higher API values. Values below 10 API indicate heavier-than-water fluids.
Conversion formulas
SG (dimensionless) = density / density of water at reference conditions.
kg/m³ = SG × 1000
lb/ft³ = SG × 62.428
ppg (lb/gal) = SG × 8.33
g/cc = SG (numerically identical)
API Gravity = 141.5 / SG - 131.5
psi/ft = SG × 0.4335
kPa/m = SG × 9.80665
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Book a free strategy call →Density and Specific Gravity in Petroleum Engineering
Density is one of the most fundamental fluid properties in petroleum engineering. It governs hydrostatic pressure in wellbores, affects flow behavior in tubing and pipelines, determines separation efficiency in surface facilities, and is a key input to nearly every reservoir, drilling, and production calculation. Unfortunately, the industry uses a wide variety of density units depending on the discipline and geography, making conversion a daily task for engineers.
Specific gravity (SG) is a dimensionless ratio of a substance's density to the density of water at standard conditions. In the oilfield, mud weight is commonly expressed in pounds per gallon (ppg) in North America, while pressure gradients are given in psi/ft or kPa/m. API gravity is an inverse density scale developed by the American Petroleum Institute, where lighter oils have higher API values (light crude is typically 35-45 API, heavy oil is below 22 API, and bitumen is below 10 API).
This converter handles all common density units used in drilling, production, and reservoir engineering. Enter a value in any field and all others update instantly. The preset buttons provide common reference densities for quick access.
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