Architects Estimator Tape & Engineers Estimators Tape each have 3 measuring tapes equaling 24” in length. The architect’s tape measure has 12 sets of graduations: 16, 3, 1½, 1, ½, ¼, 1/8, 1/16, ¾, 3/8, 3/16, 3/32 to the foot. And the Engineering tape measure has 6 graduations: 10, 20, 30, 40, 50, 60 parts per inch. Both tapes conveniently fit in your pocket and are useful for reading blueprints.