How do I use the Gas Density Calculator?

Enter the absolute pressure in pascals (Pa), the molar mass in kilograms per mole (kg/mol), and the absolute temperature in kelvin (K). The calculator will compute the density using the ideal gas law.

What is the formula used for gas density?

The calculator uses the ideal gas law: density = (pressure * molar mass) / (universal gas constant * temperature). The universal gas constant is 8.314 J/(mol·K).

Can I use this calculator for real gases?

This calculator assumes ideal gas behavior. For real gases at high pressure or low temperature, results may deviate. It is best for approximate calculations under normal conditions.

Physics

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Gas Density Calculator.

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

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Set your values

Results update as you type.

02 / ANSWER

Absolute pressure

Molar mass

Absolute temperature

Gas density

1.225215kg/m³

Results update automatically as you type.

Use Cases

Engineering and Design Calculations

Quickly estimate gas density for piping, ventilation, or storage design when ideal gas behavior is acceptable.

Example: Estimate the density of nitrogen at 101325 Pa and 300 K.

Educational Physics and Chemistry

Help students understand the relationship between pressure, temperature, molar mass, and gas density.

Example: Calculate the density of oxygen at 200000 Pa and 350 K.

Frequently Asked Questions

How do I use the Gas Density Calculator?: Enter the absolute pressure in pascals (Pa), the molar mass in kilograms per mole (kg/mol), and the absolute temperature in kelvin (K). The calculator will compute the density using the ideal gas law.
What is the formula used for gas density?: The calculator uses the ideal gas law: density = (pressure * molar mass) / (universal gas constant * temperature). The universal gas constant is 8.314 J/(mol·K).
Can I use this calculator for real gases?: This calculator assumes ideal gas behavior. For real gases at high pressure or low temperature, results may deviate. It is best for approximate calculations under normal conditions.

Tips & Common Mistakes

Tips

Ensure pressure is in pascals (Pa), not bar or atm. Convert if necessary.
Use molar mass in kg/mol. For example, oxygen is 0.032 kg/mol.
Temperature must be absolute in kelvin (K). Add 273.15 to Celsius.
For high accuracy, use the actual molar mass of the gas mixture.

Common Mistakes to Avoid

Forgetting to convert pressure to pascals (Pa) before entering.
Using molar mass in g/mol instead of kg/mol, leading to a factor of 1000 error.
Entering temperature in Celsius or Fahrenheit instead of kelvin.

Last updated: August 13, 2026