MihsabaHow to use
The ideal gas equation PV=nRT links absolute pressure, volume, amount of substance and absolute temperature. Choose the unknown, enter the other three, and the calculator converts to SI internally before solving and converting back.
- Choose pressure, volume, moles or temperature as the unknown.
- Enter the three known values and units.
- Calculate; temperature is converted to kelvin, pressure to pascals and volume to m³ internally.
How it is calculated
Example
Example: at 1 atm, 1 mol and 273.15 K, V=nRT/P≈0.022414 m³≈22.414 L.
Important notes
P in PV=nRT is absolute pressure, not gauge pressure. The ideal model can deviate from real gases, especially at high pressure or near condensation. Do not substitute it for real-gas property or safety data.
Frequently asked questions
Why must temperature be absolute?
PV=nRT requires an absolute temperature scale, so Celsius or Fahrenheit must first be converted to kelvin.
Can I use psi and cubic feet?
Yes. Selected units are converted to SI internally.
Is 1 atm equal to 101325 Pa?
Yes, that conversion is used here.
Is the ideal gas law exact for real gases?
No. It is a model; real-gas corrections may be needed at high pressure or near phase changes.
Is this calculator free?
Yes. It is free to use and requires no account.