💨Ideal Gas Law Calculator
Solve PV = nRT for pressure, volume, moles, or temperature — with full unit conversion.
Runs entirely in your browser. No data is sent to a server.
Free Ideal Gas Law Calculator
Need to solve PV = nRT but the units keep tripping you up? Our free ideal gas law calculator handles the conversions for you. Enter any three of pressure, volume, moles, or temperature — in whichever units you have — and it solves for the missing value using the correct gas constant automatically.
All pressure, volume, and temperature units are converted internally before solving, and temperature is always checked against absolute zero to catch impossible inputs. Every step is shown, from unit conversion through to the final rearranged formula, so you can follow exactly how the answer was reached. A quick STP toggle is included for standard-condition problems.
Perfect for chemistry and physics coursework, it runs entirely in your browser. No sign-up, no downloads, no limits. See the About page or the FAQ for more.
About the Ideal Gas Law Calculator
Features
Solve for any variable
Pressure, volume, moles, or temperature.
Multi-unit support
Automatic conversion across common units for each quantity.
Absolute-zero validation
Temperatures below 0 K are rejected.
STP shortcut
One click sets 0°C and 1 atm.
Frequently Asked Questions
How does the ideal gas law calculator work?
Enter any 3 of pressure, volume, moles, or temperature; it solves PV=nRT for the missing value.
What units are supported?
Pressure in atm, kPa, mmHg, bar, or psi; volume in L, mL, m³, or ft³; temperature in °C, °F, or K.
Which value of R does it use?
The gas constant is automatically matched to your chosen units (e.g. 0.0821 L·atm/mol·K).
Does it convert Celsius to Kelvin automatically?
Yes, temperature is always converted to Kelvin internally before solving.
What happens if I enter a temperature below absolute zero?
It's rejected as physically impossible, with a clear message.
Is there a shortcut for STP problems?
Yes, a toggle sets standard conditions (0°C, 1 atm) automatically.
Does it show the steps?
Yes, unit conversions and the rearranged formula with substituted values are all shown.
Is it free?
Completely free, no sign-up, downloads, or limits.
Is my data stored?
No; everything runs in your browser and isn't stored or sent anywhere.
Does it work on mobile?
Yes, fully responsive on all screen sizes.