## Calculate Specific Gravity (SG) in oilfield unit

This article demonstrates how to calculate Specific Gravity (SG) from different density or pressure gradient  in both oilfield and metric unit.

# Calculate Specific Gravity from Mud Weight In Oilfield Unit

## Calculate specific gravity using mud weight in PPG

Specific Gravity (SG) = mud weight in ppg ÷ 8.33

Example:
Mud weight = 13.0 ppg
Specific Gravity (SG) = 13.0 ppg ÷ 8.33
Specific Gravity (SG)= 1.56

## Calculate specific gravity using pressure gradient in psi/ft

Specific Gravity (SG) = pressure gradient in psi/ft ÷ 0.433

Example:

Specific Gravity (SG) = 0.50 psi/ft ÷ 0.433
Specific Gravity (SG) = 1.15

## Calculate specific gravity using mud weight in lb/ft3

Specific Gravity (SG) = mud weight in lb/ft3 ÷ 62.4

Example:

Mud weight = 90 lb/ft3
Specific Gravity (SG)= 90 lb/ft3÷ 62.4
Specific Gravity (SG) = 1.44

# Calculate Specific Gravity from Mud Weight In Metric Unit

## Calculate specific gravity using mud weight in kg/m3

Specific Gravity (SG) = mud weight in kg/m3÷ 1000

Example:
Mud density = 1200 kg/m3
Specific Gravity (SG) = 1200 kg/m3÷ 1000
Specific Gravity (SG)= 1.2

## Calculate specific gravity using mud weight in g/cc

Specific Gravity (SG) = mud weight in g/cc÷ 1.0

Example:
Mud density = 1.2 g/cc
Specific Gravity (SG) = 1.2 g/cc÷ 1000
Specific Gravity (SG)= 1.2

## Calculate specific gravity using pressure gradient in kPa/m

Specific Gravity (SG) = pressure gradient in kPa/m ÷ 9.81

Example: