Ideal Gas Law Calculator

Solve the ideal gas law PV = nRT for pressure, volume, moles, or temperature.

Pa
mol
K

The Ideal Gas Law

The ideal gas law relates the pressure, volume, amount, and temperature of an ideal gas in a single equation: PV = nRT. It combines Boyle's law, Charles's law, and Avogadro's law into one relationship and is a cornerstone of thermodynamics and chemistry.

Rearranged Formulas

  • P = nRT / V — Pressure in pascals (Pa)
  • V = nRT / P — Volume in cubic meters (m³)
  • n = PV / (RT) — Amount of substance in moles (mol)
  • T = PV / (nR) — Temperature in kelvin (K)

Symbols and SI Units

  • P — Pressure, measured in pascals (Pa)
  • V — Volume, measured in cubic meters (m³)
  • n — Amount of substance, measured in moles (mol)
  • T — Absolute temperature, measured in kelvin (K)
  • R — Universal gas constant, 8.314462618 J/(mol·K)

Worked Example

One mole of an ideal gas at standard temperature (273.15 K) occupying the molar volume of 0.022414 m³ exerts a pressure of:

  • P = nRT / V = (1 × 8.314462618 × 273.15) / 0.022414
  • P ≈ 101,325 Pa ≈ 1 atmosphere

References

The formula and physical constants used in this calculator are based on established physics principles and verified sources:

Note: This calculator assumes an ideal gas and does not account for intermolecular forces or finite molecular volume. Real gases deviate from PV = nRT at high pressures and low temperatures. Inputs and outputs use SI units.