June 8, 2026 Gas Constant Calculator Pressure (P) atm Pa kPa bar mmHg (torr) psi Volume (V) L m³ mL cm³ gal (US) ft³ Amount of substance (n) mol Temperature (T) K °C °F Calculate specific gas constant Rs Auto‑calculate live Molar mass (g/mol) Custom Air (28.97) O₂ (32) N₂ (28.01) CO₂ (44.01) He (4.00) H₂ (2.02) CH₄ (16.04) Calculate Reset Copy Results Download PDF