Ideal Gas Law Calculator

The Ideal Gas Law

PV = nRT
Where:
• P = Pressure (Pa, atm, kPa)
• V = Volume (m³, L)
• n = Number of moles (mol)
• R = Ideal gas constant
• T = Temperature (K)

Common Gas Constants (R)

• 8.314 J/(mol·K) - SI units
• 0.082057 L·atm/(mol·K) - Common chemistry
• 62.363577 L·torr/(mol·K) - mmHg units
• 1.987 cal/(mol·K) - Thermal energy
• 10.73 psi·ft³/(lbmol·°R) - Engineering units

Real Gas Corrections

Van der Waals Equation:
[P + a(n/V)²] × (V - nb) = nRT
Where a and b are gas-specific constants accounting for intermolecular forces and molecular volume.

Applications

• Chemistry: Reaction stoichiometry, gas mixtures
• Physics: Thermodynamics, kinetic theory
• Engineering: HVAC, combustion, propulsion
• Meteorology: Atmospheric science
• Medicine: Respiratory physiology

Limitations

• Assumes no intermolecular forces
• Assumes molecules have zero volume
• Works best at high temperatures and low pressures
• Real gases deviate at high pressures and low temperatures