Ideal Gas Law Calculator
Ideal Gas Law Calculator finds the number of moles of a gas from its pressure in atmospheres, volume in liters, and temperature in kelvin using n = PV/RT.
What this calculator does
The Ideal Gas Law Calculator estimates your result instantly from the values you enter, using standard science & engineering formulas. Ideal Gas Law Calculator finds the number of moles of a gas from its pressure in atmospheres, volume in liters, and temperature in kelvin using n = PV/RT. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Ideal Gas Law Calculator
This calculator solves the ideal gas law, PV = nRT, for the amount of gas in moles.
Supply pressure in atmospheres, volume in liters, and temperature in kelvin, and it returns n using R = 0.082057 L·atm/mol·K.
Formula & Mathematical Calculation
Moles (n) = f(Pressure (atm), Volume (L), Temperature (K))
Calculated according to standard science formulas implemented in the calculator core.
Calculation Example
For P = 1 atm, V = 22.4 L and T = 273.15 K:
n = (1 × 22.4) ÷ (0.082057 × 273.15) = 22.4 ÷ 22.4139 = 0.99938 mol.
Key Benefits
- Solves PV = nRT for moles in one step
- Uses R = 0.082057 L-atm/mol-K to match atm and liter inputs
- Requires temperature above 0 K to avoid invalid results
- Reports moles to five decimal places
How to Use this Calculator
-
Enter pressure
Type the pressure in atmospheres in the Pressure field. -
Enter volume
Type the volume in liters in the Volume field. -
Enter temperature
Type the absolute temperature in kelvin in the Temperature field. -
Calculate
Select Calculate and read Moles (n) in the result box.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Ideal Gas Law Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.