A measuring device for measuring nuts, bolt heads, washers and the like that includes a body having a first end, an opposing second end, and a longitudinal reference line extending between the first end and the second end; a first pair of parallel surfaces of equal length, the first pair of opposing parallel surfaces longitudinally between the first end and the second end, the surfaces of the first pair spaced apart by a first distance; a second pair of parallel surfaces of equal length, the second pair of parallel surfaces longitudinally between the first pair of parallel surfaces and the first end, the surfaces of the second pair spaced apart by a second distance that is smaller than the first distance; and a pair of nonparallel surfaces connected at an obtuse angle, the opposing nonparallel surfaces longitudinally between the second pair of opposing parallel surfaces and the first end.