What is calculated?
For a fixed amount of gas, pV/T remains constant in the ideal model. Temperatures and pressures must be absolute.
Equations
p₁V₁/T₁ = p₂V₂/T₂
V₂ = V₁·(p₁/p₂)·(T₂/T₁)
Fluid dynamics & thermodynamics · preliminary design
Ideal gas state change
Calculate the new volume of a fixed gas mass after pressure and temperature change.
IJ 5
02
Results
Enter values and run the calculation.
Application and limits
Compressed-air volume, gas-spring pre-estimates and temperature-related volume change.
Ideal gas, fixed mass, equilibrium states; no condensation, leakage or real-gas correction.
Frequently asked questions
Why absolute pressure?
The equation references vacuum; 5 bar gauge is about 6 bar absolute.
When does the model fail?
Near condensation and at high density, real-gas data are required.
Technical basis
Dubbel, thermodynamics, ideal-gas thermal equation of state (local source, 2026-09-09).
The source supports the equation structure; this calculator does not claim a complete standards verification.