Charles's Law Calculator

About this calculator

Charles's law describes how a fixed amount of gas at constant pressure expands or contracts as its temperature changes: V₁/T₁ = V₂/T₂, where volumes and temperatures must be in an absolute scale (Kelvin) for the direct proportionality to hold. It's one of the classic gas laws — alongside Boyle's law (pressure-volume) and Gay-Lussac's law (pressure-temperature) — that together form the ideal gas law, PV = nRT.

Chemistry students and engineers use Charles's law to predict how a hot-air balloon expands as the air inside is heated, why a sealed container of gas should never be heated in a fire (the pressure/volume relationship can cause it to rupture), and to solve textbook problems converting a gas's volume between two temperatures at constant pressure. Enter the initial volume and temperature and the new temperature to find the new volume.