Calculate pressure using the ideal gas law. Enter moles, temperature, and volume to solve for ideal gas pressure in PSI, kPa, pascals, bar, atmospheres, mmHg, torr, and inches of water column.
Moles:
Enter how much gas is in the container. More gas particles create more pressure when volume and temperature stay the same.
Temperature:
The calculator converts the temperature to Kelvin because gas law calculations use absolute temperature.
Volume:
Enter the container volume. Smaller volume increases pressure for the same amount of gas and temperature.
An ideal gas pressure calculator is useful for chemistry homework, physics examples, sealed container estimates, lab calculations, pressure conversions, and checking how moles, volume, and temperature affect pressure.
The ideal gas law is a model. Real gases can differ from ideal behavior at high pressure, low temperature, or near condensation.
The ideal gas pressure formula is:
P = nRT ÷ V
Use P = nRT ÷ V. Multiply moles by the gas constant and absolute temperature, then divide by volume.
The ideal gas law gives absolute pressure. Gauge pressure is found by subtracting atmospheric pressure.
If moles and volume stay the same, gas pressure rises as absolute temperature rises.
If moles and temperature stay the same, gas pressure increases when volume decreases.