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Ideal Gas Density Calculator.

Calculate ideal-gas density from pressure, molar mass, and absolute temperature.

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Density: 1.225215

Density

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Educational SI models with assumptions stated in each description; verify engineering decisions independently.

Use Cases

Engineering gas flow calculations

Determine gas density for pipeline design, compressor sizing, or mass flow calculations in industrial processes.

Example: Calculate density of nitrogen at 200 kPa and 300 K.

Educational physics experiments

Verify theoretical density values in thermodynamics labs or classroom demonstrations using measured pressure, temperature, and molar mass.

Example: Check density of helium at room temperature and atmospheric pressure.

Frequently Asked Questions

What is the ideal gas density formula?
The calculator uses the ideal gas law: density = (Pressure × Molar mass) / (Universal gas constant × Temperature). Here, pressure is in Pa, molar mass in kg/mol, and temperature in K.
What units should I use for pressure, molar mass, and temperature?
Enter pressure in pascals (Pa), molar mass in kilograms per mole (kg/mol), and absolute temperature in kelvin (K). The calculator returns density in kg/m³.
Can I use this calculator for real gases?
This calculator assumes ideal gas behavior. For real gases at high pressure or low temperature, deviations may occur. For most conditions, it provides a good approximation.

Tips & Common Mistakes

Tips

  • Ensure temperature is in kelvin (K). Convert Celsius to K by adding 273.15.
  • Use consistent units: pressure in Pa, molar mass in kg/mol, and temperature in K to get density in kg/m³.
  • For air, use molar mass ≈ 0.02897 kg/mol for accurate results.
  • Double-check your pressure value: 1 atm = 101,325 Pa.

Common Mistakes to Avoid

  • Forgetting to convert pressure to pascals (Pa) when using atm or bar.
  • Using molar mass in g/mol instead of kg/mol (divide by 1000).
  • Using Celsius temperature instead of kelvin (K).

Last updated: August 13, 2026