Ideal Gas Law Calculator

What is the Ideal Gas Law Calculator?

Solve PV = nRT for pressure given moles, temperature and volume. PV = nRT links pressure, volume, temperature and amount of gas, a cornerstone of chemistry, engineering and weather science.

How to use the Ideal Gas Law Calculator

1. Enter your amount, your temperature, your volume.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: pressure, in atm.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With amount = 1 mol, temperature = 298.15 K, volume = 22.4 L, the Ideal Gas Law Calculator returns pressure: 110,667.72 Pa; in atm: 1.09221 atm.

Where the Ideal Gas Law Calculator helps in real life

A chemistry student needs the pressure of 2 moles of gas in a 10-liter container at 25 °C. The calculator converts the temperature to kelvin and applies the gas constant to give the answer.

An engineer estimates how much the pressure in a sealed tank will rise on a hot day. Running the calculation at two temperatures shows the change.

Common mistakes to avoid

• Using degrees Celsius instead of kelvin.
• Pairing liters with a value of R meant for cubic meters.
• Applying the ideal gas law at very high pressures or very low temperatures.
• Mixing gauge pressure with absolute pressure.

💡 Practical tip: Temperature must be in kelvin — entering 25 instead of 298 gives an answer more than ten times too small.

Tips for better results

• Add 273.15 to a Celsius temperature to get kelvin.
• Check that the units of R match your inputs.
• Treat results as approximations for real gases under extreme conditions.

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