Calculators › API Gravity Calculator
⚗️

API Gravity Calculator

Petroleum Density per API MPMS

Advertisement
API Gravity Converter
Converts between API gravity and specific gravity for crude oil and petroleum products using the standard API formula. Essential for density corrections and custody transfer calculations.

Input Parameters

-

About API Gravity

API gravity is an inverse measure of petroleum liquid density relative to water. Higher API gravity indicates lighter (less dense) petroleum products.

Typical API Gravity Values

• Light Crude: 35-45 °API
• Medium Crude: 25-35 °API
• Heavy Crude: 10-25 °API
• Condensate: 50-70 °API
• Water: 10 °API (SG = 1.0)

Advertisement

Formulas

°API = (141.5 / SG) - 131.5
SG = 141.5 / (°API + 131.5)
°API = API Gravity
SG = Specific Gravity (60°F/60°F)

Standards & References

  • API MPMS Chapter 11
    Physical Properties Data
  • ASTM D1298
    Density, Relative Density, or API Gravity
  • ASTM D4052
    Density and Relative Density by Digital Densitometer

Important Notes

  • API gravity is measured at standard temperature of 60°F (15.56°C)
  • Water has an API gravity of 10° (SG = 1.0 at 60°F/60°F)
  • Lighter products have higher API gravity values
  • API gravity affects pricing - lighter crudes typically command premium prices
  • Temperature corrections are critical for accurate custody transfer measurements
Advertisement

Related Calculators

💨

Gas Density

Calculate gas density from pressure and temperature
🌡️

Vapor Pressure

Calculate vapor pressure of petroleum liquids
⚡

Energy Conversion

Convert between energy units
🧪

Ideal Gas Law

PV=nRT calculations