What's the Legal Age to Buy Vape? Vaping Laws Explained. U.S. Raises Tobacco Buying Age to 21 WSJ Vaping Resources in Greater Cincinnati New Study: Parent Knowledge of the U.S. Tobacco 21 Law Do you know the legal age to purchase tobacco in the U.S.? It turns out many parents don't. In a survey 8 in 10 Support raising the minimum age to purchase tobacco products, e cigarettes, and vaping devices to 21 Tobacco 21 Selectmen in favor of raising e cig purchasing age