Ideal Gas Law Calculator
Solve PV = nRT for any unknown.
Enter your values
Enter the pressure in Pa.
Enter the volume in m³.
Enter the temperature in K.
Choose one of: Moles, Pressure, Volume, Temperature.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Moles
- 0.999377 mol
- Pressure
- 101325 Pa (1 atm)
- Volume
- 0.0224 m³ (22.4 L)
- Temperature
- 273.15 K (0 °C)
- Molar volume
- 22.414 L/mol
Working
- 1n = PV ÷ RT = (101325 × 0.0224) ÷ (8.314 × 273.15) = 0.99938 mol
Quick answer
PV = nRT, with R = 8.314 J/(mol·K) when pressure is in pascals and volume in cubic metres.
PV = nRT
At a glance
| What it does | Solve PV = nRT for any unknown. |
|---|---|
| Category | Chemistry |
| Inputs needed | Pressure, Volume, Temperature, Solve for |
| Main output | Moles |
| Formula | PV = nRT |
| Cost | Free — no sign-up, no download |
How to use the Ideal Gas Law Calculator
- 1Enter pressure in pascals and volume in cubic metres.
- 2Enter temperature in kelvin.
- 3Pick which variable to solve for.
Inputs explained
- Pressure(Pa)
- Enter the pressure in Pa.
- Volume(m³)
- Enter the volume in m³.
- Temperature(K)
- Enter the temperature in K.
- Solve for
- Choose one of: Moles, Pressure, Volume, Temperature.
Worked example
Using the values the calculator loads with:
Inputs
- Pressure101325 Pa
- Volume0.0224 m³
- Temperature273.15 K
- Solve forMoles
Results
- Moles0.999377 mol
- Pressure101325 Pa (1 atm)
- Volume0.0224 m³ (22.4 L)
- Temperature273.15 K (0 °C)
- Molar volume22.414 L/mol
- n = PV ÷ RT = (101325 × 0.0224) ÷ (8.314 × 273.15) = 0.99938 mol
Frequently asked questions
What is molar volume at STP?
22.4 L/mol at 0°C and 1 atm — one of the most-used numbers in chemistry.
When does the ideal gas law fail?
At high pressure or low temperature, where molecular volume and attraction matter — use van der Waals then.
What do I need to enter into the Ideal Gas Law Calculator?
Just 4 values: pressure, volume, temperature, solve for. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Ideal Gas Law Calculator work out the answer?
PV = nRT, with R = 8.314 J/(mol·K) when pressure is in pascals and volume in cubic metres. It applies the formula PV = nRT and shows the working so you can check each step by hand.
Is the Ideal Gas Law Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.