Ideal Gas Law Calculator
Solve one of pressure, volume, amount, or temperature from PV = nRT. R is 8.314462618 J/(mol K). Informational, not a pressure-vessel rating, wiring approval, or lab protocol.
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How to use the ideal gas calculator
- Pick which quantity to solve: P, V, n, or T.
- Fill the other three. Leave the unknown blank.
- Set pressure, volume, and temperature units. Amount is moles.
- Read PV = nRT with R = 8.314462618. Nothing is uploaded.
Ideal gas law
PV = nRT
| P | Absolute pressure, converted to pascals |
|---|---|
| V | Volume, converted to cubic meters |
| n | Amount of substance in moles |
| T | Absolute temperature in kelvin |
| R | 8.314462618 J/(mol K) |
| Model | Ideal gas. No van der Waals terms. |
What PV = nRT is
The ideal gas law ties pressure, volume, moles, and temperature. R is 8.314462618 J/(mol K). The default leaves P blank, with V = 1 m3, n = 1 mol, T = 273.15 K, so P is n R T / V.
Pressure, volume, mole, and kelvin
Pressure on this page is absolute, not gauge. Volume is the container size. n is moles, not grams. Temperature converts to kelvin before the product. Mass density without a gas model is density.
How this page converts units
Pa, kPa, bar, and atm convert to pascals. m3 and L convert to cubic meters (1 L = 0.001 m3). Celsius becomes kelvin by adding 273.15. The solve control names the unknown even if that field still has a leftover number.
Limits
Ideal gas only. High pressure and low temperature need a better equation of state. Informational, not a vessel rating, wiring approval, or lab protocol. CZNull does not receive the values. See the disclaimer.