When instructed to work to a specific measurement, do not actually measure! Instead, based on your blocked row gauge, calculate how many rows you need to work. That way your finished piece will be the length needed. For instance, at a blocked row gauge of 6 rows to 1″/2.54 cm, to knit 0.75″ / 1.9 cm, multiply 6 x 0.75 = 4.5 rows. Work to end with the row specified.