Overview

Calculate pressure, volume, temperature, or amount of substance using the ideal gas law (PV = nRT). An essential tool for gas-related calculations in chemistry, physics, and engineering.

Formula

PV = nRT

P = Pressure (Pa or atm)
V = Volume (L or m³)
n = Amount of substance (mol)
R = Gas constant = 8.314 J/(mol·K) = 0.08206 L·atm/(mol·K)
T = Absolute temperature (K)

Temperature conversion: T(K) = T(°C) + 273.15

How to Use

1. 1Select the variable to solve for (P, V, n, or T).
2. 2Enter the other three known values.
3. 3Choose Kelvin (K) or Celsius (°C) for temperature.
4. 4Select pressure units (Pa, atm, kPa).
5. 5View the calculated result.

Tips

• ✔At STP (0°C / 273.15 K, 1 atm), 1 mol of an ideal gas occupies 22.4 L.
• ✔Temperature must always be in Kelvin (K) for this equation.
• ✔1 atm = 101,325 Pa = 101.325 kPa.
• ✔Real gases deviate significantly from ideal behavior at high pressures and low temperatures; use the Van der Waals equation for corrections.

FAQ