A device for calibrating a multi-roll leveler for leveling a metal strip includes an assembly having two series of rolls, namely upper rolls and lower rolls which face each other so as to imbricate the rolls of one series into those of the other. The series of rolls are placed substantially parallel to each other and perpendicular to the run direction of the strip to be leveled. A rigid measurement bar of sufficient length is positioned in the leveling direction between the upper and lower rolls, extending over all the rolls, and having rigid protrusions integral with the bar reproducing, when they are placed plumb with the lower rolls, the action of the lower rolls and their mechanical properties. A thin metal plate rests on these protrusions and is fastened to one of them at around the middle of the bar and includes extensometers for measuring its elastic deformations.