Science & Engineering

Partial Pressure Calculator (Dalton & Ideal Gas)

Finds the partial pressure of a gas in a mixture two ways. Use Dalton's law from mole fraction and total pressure, or the ideal gas law from moles, volume, and temperature.

How to use
  1. Pick the Dalton's law or ideal gas mode.
  2. Enter the required values for that mode.
  3. Choose your pressure units.
Air gas
Partial pressure
0.2095 atm

x = 0.2095 · P_total = 1 atm

In mmHg
159.22
In kPa
21.226
In psi
3.0788
For study and estimation. Verify against authoritative data before relying on a result.
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Common questions

What is Dalton's law of partial pressures?

Each gas in a mixture contributes a pressure equal to the total pressure times its mole fraction. The partial pressures sum to the total.

When should I use the ideal gas method instead?

Use it when you know the moles, volume, and temperature of one gas directly. It applies P = nRT/V to that single component.

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