Ideal Gas Law Calculator

PV = nRT — solve pressure, volume, moles or temperature

Quick Answer

Ideal Gas Law Calculator: PV = nRT — solve pressure, volume, moles or temperature. Solve any of P, V, n, T from the other three; T(K) = °C + 273.15.

V（L）

n（mol）

T（°C）

PV = nRT → Pressure

101.4 kPa

Steps

1P = nRT/V
2= 1 × 8.314 × 273.15 ÷ 22.4
3= 101.383 kPa（= 1.001 atm）

Key values

R8.314 J/(mol·K) = 8.314 kPa·L/(mol·K) = 0.08206 atm·L/(mol·K)

STP0°C, 101.325 kPa → 1 mol = 22.4 L

SATP25°C, 100 kPa → 1 mol = 24.8 L

Units1 atm = 101.325 kPa = 760 mmHg = 1.013 bar

💡 The ideal gas law works well at low pressure / high temperature; near liquefaction (high P, low T) use van der Waals. Temperature MUST be absolute (Kelvin) — a classic exam trap. Real-life: a car tire at 250 kPa holds ~4 mol of air; heating from 20°C to 40°C raises pressure ~7%.

Was this tool helpful?

How to Use

Enter known quantities: fill values and confirm units in the Ideal Gas Law Calculator.
Instant solution: unknowns solve live with the formula shown transparently.
Use constant/material tables: standard physical constants and material data are listed on this page.
Compare conditions: change inputs to compare scenarios.

Key Points

Ideal Gas Law Calculator is a free online science & engineering tool — open and use, no sign-up.
All calculations run locally in your browser; your data never leaves the device.
Key capability: PV = nRT — solve pressure, volume, moles or temperature.
Results come with formulas and reference tables so you can verify every number.

Formula & How It Works

Ideal gas law

PV = nRT, R = 8.314 J/(mol·K)

Solve any of P, V, n, T from the other three; T(K) = °C + 273.15

STP anchor: 1 mol = 22.414 L at 0 °C and 101.325 kPa

FAQ

How do I use the Ideal Gas Law Calculator?

Open the page and fill in the input fields — results update automatically. PV = nRT — solve pressure, volume, moles or temperature.

Are the results accurate?

Yes. Standard formulas and conversion factors are used and verified.

Is it free? Do I need to sign up?

Completely free. No registration, login or download required.

Does it work on mobile?

Yes. The responsive design works on phones, tablets and desktops.

Is my data saved?

No. Everything runs locally in your browser.

Related Guides

Source & Updates

Based on CODATA recommended constants and standard physics formulas. Last updated: 2025-07

Last updated: 2026-08-04

Formulas and content on this page are reviewed by the YiJianSuan team. For reference only — official sources prevail.

Cite this page: YiJianSuan. Ideal Gas Law Calculator[EB/OL]. https://www.yijiansuan.com/en/c/science/ideal-gas

Results provided by this tool are for reference only and do not constitute professional advice.