Gas Laws & Fluid Behavior Calculators
All gas laws & fluid behavior calculators in one place.
Ideal Gas Law Solver
Solve PV = nRT for pressure, volume, temperature, or moles of gas — enter mass and molar mass instead of moles (type a chemical formula and the molar mass fills itself in), quick-fill STP, IUPAC STP, NTP, or room conditions, and get gas density with full step-by-step working.
Ideal Gas Pressure Calculator
Find gas pressure from PV = nRT, from a pressure/volume/temperature change, or from a partial pressure using Dalton's Law, with full step-by-step working.
Ideal Gas Volume Calculator
Find gas volume from PV = nRT, from a pressure/temperature change, or from a change in moles using Avogadro's Law, with full step-by-step working.
Ideal Gas Temperature Calculator
Find gas temperature from PV = nRT, from a pressure/volume change, or at constant volume using Gay-Lussac's Law, with full step-by-step working.
Combined Gas Law Calculator
Calculate final pressure, volume, or temperature using P1V1/T1 = P2V2/T2, with worked steps and a labelled gas-state diagram.
Boyle's Law Calculator
Calculate final pressure or volume of a gas at constant temperature using P1V1 = P2V2, with worked steps and a labelled piston diagram.
Charles's Law Calculator
Calculate final gas volume or temperature at constant pressure using V1/T1 = V2/T2, with worked steps and a labelled heated-gas diagram.
Gay-Lussac's Law Calculator
Calculate final pressure or temperature of a gas at constant volume using P1/T1 = P2/T2, with worked steps and a labelled sealed-container diagram.
Avogadro's Gas Law Calculator
Calculate final volume, final moles, initial volume, or initial moles of a gas at constant pressure and temperature using V1/n1 = V2/n2, with worked steps and a labelled particle-count diagram.
Van der Waals Real Gas Solver
Solve the Van der Waals real-gas equation (P + an²/V²)(V − nb) = nRT for pressure, volume, or temperature, with built-in constants for 14 common gases or your own custom a and b, a side-by-side comparison against the ideal gas law, the compressibility factor Z, and full step-by-step working.
Dalton's Law of Partial Pressures
Add up partial pressures to find total pressure, or solve for a partial pressure, mole fraction, or total pressure using Pi = xi × P_total, with worked steps and a labelled gas-mixture diagram.
Graham's Law of Effusion & Diffusion
Calculate effusion/diffusion rate or molar mass of a gas using Rate1/Rate2 = √(M2/M1), with worked steps and a labelled effusion-race diagram.
Gas Density & Molar Mass Calculator
Find the density of any gas from its molar mass, or work out an unknown gas's molar mass from a measured density, using ρ = PM/RT, with STP/NTP/SATP quick-fill conditions, a closest-common-gas match, a density-relative-to-air comparison, and full step-by-step working.
Root Mean Square (RMS) Speed of Gas
Calculate the root-mean-square (RMS) speed of gas molecules using vrms = √(3RT/M), plus the average speed and most probable speed from kinetic theory, from a chemical formula or molar mass and any temperature, with full step-by-step working.
STP / NTP Gas Volume Unit Converter
Convert a gas volume between STP, IUPAC STP, NTP, SATP, or any custom temperature and pressure using the combined gas law, convert freely between mL, L, m³, cm³, ft³, in³, and US gallons/quarts, and see the molar volume at both conditions, with full step-by-step working.