What this PV nRT calculator does
This PV nRT calculator (also called PV=nRT calculator, PV = nRT calculator, ideal gas law calculator, or gas law calculator) finds the one unknown quantity in the equation PV = nRT when the other three are known. You choose whether to solve for pressure (P), volume (V), moles (n), or temperature (T), then enter the three known values. The PV nRT calculator converts everything to consistent units, performs the calculation, and returns the answer in the unit you select.
PV = nRT formula (used by this PV nRT calculator)
The ideal gas law says that pressure times volume equals moles times the gas constant times temperature. In symbols:
PV = nRT
Where:
- P = pressure
- V = volume
- n = number of moles of gas
- R = universal gas constant
- T = temperature (must be in Kelvin for the formula)
The gas constant R
R is a fixed constant: it has units of energy per degree of temperature per mole. It is often called the universal gas constant, ideal gas constant, or molar gas constant. Its numerical value depends on the units you use for P, V, and T. Reference tables list R in many forms (e.g. J/(mol·K), L·atm/(mol·K)).
This calculator uses R = 8.31446261815324 m³·Pa·K⁻¹·mol⁻¹ (SI). All your inputs are converted into these units for the calculation; the result is then converted back into whatever output unit you choose (atm, L, °C, etc.), so you can work in the units you like.
How the ideal gas calculator solves for each variable
From PV = nRT we rearrange to get one variable on the left and the others on the right. This ideal gas law calculator uses these forms:
- Pressure: P = nRT / V — when you know volume, moles, and temperature.
- Volume: V = nRT / P — when you know pressure, moles, and temperature.
- Moles: n = PV / (RT) — when you know pressure, volume, and temperature.
- Temperature: T = PV / (nR) — when you know pressure, volume, and moles. (Result is in Kelvin; we convert to °C or °F if you prefer.)
When is the ideal gas law (and this gas law calculator) accurate?
The ideal gas law works best at moderate pressures and temperatures, where gas particles are far apart and behave like point masses. At high pressure or low temperature, real gases deviate from this behavior; then models such as the van der Waals equation are more accurate.
Who uses this ideal gas calculator?
Chemists use the ideal gas law calculator for reaction stoichiometry, gas yields, and behavior in flasks and reactors. Engineers use this gas law calculator for compressors, pipelines, and pressure vessels. Students use the ideal gas calculator in homework and exams. This free tool runs in your browser with no sign-up or download and gives results in your chosen units.
PV nRT calculator, PV=nRT calculator, and PV = nRT calculator
Whether you search for PV nRT calculator, PV=nRT calculator, PV = nRT calculator, ideal gas law calculator, gas law calculator, or ideal gas calculator—they all mean the same thing: a tool that solves PV = nRT for P, V, n, or T. This page is your PV nRT calculator with multiple units and instant results.
Ideal gas calculator vs gas law calculator
The terms ideal gas law calculator, gas law calculator, and ideal gas calculator are used interchangeably. All refer to a PV nRT calculator that solves the ideal gas law PV = nRT. This page provides a single PV=nRT calculator that handles all four variables (P, V, n, T) with multiple unit options, so you get an accurate PV = nRT calculator for any chemistry or physics need.
Why use this PV nRT calculator?
This PV nRT calculator (or PV=nRT calculator / PV = nRT calculator) is free, requires no sign-up, and supports pressure in Pa, kPa, bar, atm, mmHg, psi; volume in m³, L, mL, cu ft, gallons; and temperature in Kelvin, Celsius, or Fahrenheit. It uses R = 8.314462618 m³·Pa·K⁻¹·mol⁻¹ for accurate calculations. Whether you search for PV nRT calculator, PV=nRT calculator, ideal gas law calculator, or gas law calculator, this tool delivers instant, correct results.