Home › Geometry › Ideal Gas Law Calculator
Ideal Gas Law Calculator
Enter moles, volume and temperature — pressure appears instantly.
Formula
PV = nRT | P = nRT / V (R = 8.314 J/mol·K)
Check value
1 mol at 273.15 K in 22.414 L → P = 101.325 kPa = 1 atm (the molar volume at STP).
FAQ
When does the ideal gas assumption fail?
At high pressure or near condensation — real-gas corrections (van der Waals) are needed. For air at room conditions it is accurate to ~1%.
What units must I use?
SI-consistent: moles, kelvin, m³ (the calculator takes liters and converts internally), giving pascals.