A method and an apparatus for measuring the amount (CW) of a coating (2) on a paper web (1). The amount (CA) of at least one component in the coating (2) on the paper web (1) is measured and the composition (CC) of the coating (2) to be transferred to the paper web (1) is determined. The amount (CW) of the coating (2) on the paper web (1) is determined on the basis of the amount (CA) of at least one component in the coating (2) on the paper web (1) and the composition (CC) of the coating (2) to be transferred to the paper web (1).
