The invention discloses a measuring tool for measuring the vertical height of a measuring instrument, and pertains to the field of measurement. The measuring tool comprises a housing, a cover, a baseboard, a ruler, a locating pin, a knob, a handle and a bubble. The ruler is packaged in the housing through the cover. The upper end of the housing is provided with a stretching opening. The ruler can be pulled out upwardly and vertically through the stretching opening. The baseboard is fixed on the bottom portion of the housing. One side of the housing which is away from the ruler is provided with the locating pin. The locating pin can be moved horizontally relative to the baseboard. The locating pin is fixed with the housing through the knob. The axis of the locating pin is vertical to the baseboard. The handle is connected with the housing. The horizontal plane on which the handle is connected with the housing is provided with the bubble. According to the invention, through the structure, the vertical height of the measuring instrument can be measured directly, and the advantage of accurate measurement can be realized. Moreover, the measuring tool of the invention has advantages of reasonable structure and convenient field carry, and is suitable for the vertical height measurement of various surveying and mapping equipment.