The purpose of the present invention is to provide a device for calculating component-suction-position height, said device enabling the height of a plurality of component suction positions to be calculated by measuring the height at two points on a tape feeder. Accordingly, a plurality of sprockets (42) are provided inside a feeder main body (13), in a width direction intersecting a supply direction of a component supply tape (12). The plurality of sprockets are used to respectively arrange, in prescribed positions separated in the width direction, a plurality of component suction positions (P1-P6) where components are to be supplied. An upper cover plate (39), which covers an upper surface of the feeder main body, and which is provided with a plurality of openings (40) located in positions corresponding respectively to the plurality of component suction positions, is affixed to the feeder main body. A height-position detection means (114) is provided which measures height positions of an upper surface of the upper cover plate at two or more places separated in the width direction. Furthermore, an interpolation calculation means (step (106)) is provided which uses interpolation calculation to calculate height positions of the plurality of component suction positions, on the basis of the upper-cover-plate height positions detected at the two or more places by the height-position detection means.