A method and a device for calculating a consumed lifespan are provided. The method includes: controlling an electric motor of a purifier to rotate at a predetermined speed; acquiring a value of a sampled parameter of the electric motor, the sampled parameter being at least one of a sampled current and a sampled voltage of the electric motor; and determining a consumed lifespan of the purifier according to the acquired value of the sampled parameter, wherein the consumed lifespan is in positive correlation with the acquired value of the sampled parameter.