Ideal Gas Law Calculator
Solve for pressure, volume, moles or temperature using the ideal gas law PV = nRT.
Assumptions used in this calculation
- Ideal gas behavior: Assumes ideal gas behavior (no intermolecular forces, negligible particle volume), most accurate at low pressure and moderate-to-high temperature.
About this calculator
The ideal gas law PV = nRT links four variables at once, so solving for anything other than pressure requires rearranging the equation and correctly handling the gas constant R, whose value changes depending on which units you're using for pressure and volume, a frequent source of errors that throw a result off by orders of magnitude. This calculator solves PV = nRT for pressure, volume, moles, or temperature, whichever one you're missing, using the gas constant R = 0.0821 L·atm/(mol·K) so pressure is in atmospheres, volume in litres, and temperature in kelvin throughout. It's built for chemistry and physics students working through stoichiometry or gas-law problems, or anyone checking a real-world scenario like the pressure inside a sealed container at a given temperature, sparing you from remembering which version of R corresponds to which unit system and from the algebra of isolating a variable buried inside a product of three others.
Worked example
1 mol at 273.15K, 22.4L (STP)
Result: 1.0 atm
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