physics calculator
Ideal Gas Volume Calculator
Calculate ideal-gas volume from amount, absolute temperature, and absolute pressure.
Ideal Gas Volume Calculator
Ideal-gas volume
Enter amount, kelvin temperature, and absolute pressure.
Uses the ideal-gas model. Real gases may differ at high pressure or near condensation.
Formula version 1.0.0
How to use this calculator
- Enter the gas amount in moles.
- Enter absolute temperature in kelvin.
- Enter absolute pressure and select its unit.
- Calculate and read the modelled volume in litres from V = nRT/P.
Symbols and units
| Symbol | Meaning | Unit or domain |
|---|---|---|
V | Ideal-gas volume | L |
n | Amount of gas | mol |
R | Molar gas constant | pressure·L/(mol·K) |
T | Absolute temperature | K |
P | Absolute pressure | selected pressure unit |
Checked examples
Standard-atmosphere example
Inputs: 1 mol, 273.15 K, 101.325 kPa
Calculation: V = nRT/P with the pressure converted consistently
Result: ≈22.41397 L
The ideal model predicts the familiar near-standard molar volume.
Check: ideal-gas-volume.test.ts
One atmosphere at 300 K
Inputs: 1 mol, 300 K, 1 atm
Calculation: V = 1×R×300÷1 atm
Result: ≈24.61721 L
Equivalent kPa input produces the same result.
Check: ideal-gas-volume.test.ts
Assumptions, rounding, and limits
- Temperature is absolute and greater than zero kelvin.
- Pressure is absolute, not gauge pressure.
- The gas follows the ideal-gas model.
- Real-gas interactions and uncertainty are not modeled.
Frequently asked questions
Can I enter Celsius?
No. Convert to kelvin first because the law requires absolute temperature.
Can I use gauge pressure?
No. Convert gauge pressure to absolute pressure before calculating.
Why might a real gas differ?
Intermolecular forces and molecular volume become important, especially at high pressure or low temperature.
Sources and review
- OpenStax: Relating Pressure, Volume, Amount, and Temperature: The Ideal Gas Law — PV = nRT
- NIST: CODATA Value: molar gas constant — Molar gas constant
- Formula version
- ideal-gas.volume@1.0.0
- Formula review
- Equatara formula review
- Editorial review
- Equatara editorial review
- Last verified
- 2026-10-25
- Applicability
- Ideal-gas approximation using absolute temperature and pressure.
- Next review
- On material formula/source change, or by 2028-10-25.
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Found a problem?
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