About this tool
The ideal gas law relates pressure, volume, moles and absolute temperature. This calculator solves for any one variable given the other three.
Formula
P · V = n · R · T, R = 8.314462618 J/(mol·K)
Worked example
1 mol at 273.15 K and 101,325 Pa → V = nRT/P ≈ 0.02241 m³ = 22.41 L (one molar volume at STP).
Notes
The ideal gas approximation breaks down at high pressures or low temperatures. For real gases use the van der Waals equation or compressibility factors.