Ideal Gas Law (PV = nRT) Calculator
Solve the ideal gas law PV = nRT for any one of pressure, volume, amount of substance, or temperature given the other three.
Solve for
m³
mol
K
Solved from PV = nRT
- 1
Numerator n × R × T
1 × 8.314462618 × 273.15 = 2,271.0955 - 2
Pressure P = nRT / V
2,271.0955 ÷ 0.0224 = 101,388.1904
How does this calculator work?
The ideal gas law PV = nRT links a gas's pressure, volume, moles, and absolute temperature through R = 8.314462618 J/(mol·K). Choose the unknown variable, enter the other three in SI units, and the calculator rearranges the equation (P = nRT/V, V = nRT/P, n = PV/RT, or T = PV/nR) to solve it.
Formula
How this is calculated
The ideal gas law relates the pressure P (in pascals), volume V (in cubic metres), amount of substance n (in moles), and absolute temperature T (in kelvin) of an ideal gas through the universal gas constant R = 8.314462618 J/(mol·K). Pick which of the four variables is unknown, then enter the other three in SI units.
The calculator rearranges PV = nRT to isolate the chosen unknown: P = nRT/V, V = nRT/P, n = PV/(RT), or T = PV/(nR). It then reports the solved value together with all four variables so the full state of the gas is visible at once.
The model assumes an ideal gas: point particles with no intermolecular forces, valid at low pressure and high temperature relative to the gas's critical point. Temperature must be absolute (kelvin) and pressure absolute (not gauge). Division-by-zero cases — such as V = 0 when solving for P, or n = 0 when solving for T — return no result.
Frequently asked questions
SI base units: pressure in pascals (Pa), volume in cubic metres (m³), amount in moles (mol), and temperature in kelvin (K). With these, R = 8.314462618 J/(mol·K) applies directly.
PV = nRT requires absolute temperature. Using Celsius would make T zero or negative near the freezing point of water and break the proportionality, so convert with K = °C + 273.15 first.
At high pressure or low temperature, real gases deviate because molecular volume and attractive forces matter. Use a real-gas model such as van der Waals near condensation conditions.
Also known as
TG we-Calculate Editorial Team. (2026). Ideal Gas Law (PV = nRT) Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/ideal-gas-law-calculator
TG we-Calculate Editorial Team. "Ideal Gas Law (PV = nRT) Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/ideal-gas-law-calculator.
TG we-Calculate Editorial Team, "Ideal Gas Law (PV = nRT) Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/ideal-gas-law-calculator
@misc{wecalculate_ideal_gas_law_calculator, title = {Ideal Gas Law (PV = nRT) Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/ideal-gas-law-calculator}}, year = {2026}, note = {TG we-Calculate} }
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