How to use PV = nRT

The ideal gas law ties together the pressure, volume, amount, and temperature of a gas: PV = nRT. R is the gas constant; use R = 0.08206 L·atm/mol·K when pressure is in atmospheres and volume in liters, and always put temperature in kelvin (K = °C + 273.15). Rearrange for whatever you need — P = nRT/V, V = nRT/P, n = PV/RT, or T = PV/nR. As a sanity check, one mole of an ideal gas at standard temperature and pressure (273.15 K, 1 atm) occupies 22.4 L.

Uses R = 0.08206 L·atm/mol·K. For SI units (Pa, m³) use R = 8.314 J/mol·K instead.

Related tools: Molar mass & molarity · all biochem tools.