Growing up my foster mother made almost all of my clothes and she wanted to squeeze out every inch she could and sometimes, actually often times, she would either be short fabric and have to make it up other places; like in seams or hems......when I grew up and starting buying and sewing I always buy a little extra just to be sure ! If the pattern called for 1-1/2 yards she would buy 1-1/4 yd.....and actually she never saved money that way because whatever she made was skimpy......no seams to let out or hems to lengthen....she was raised during the depression and that explains a lot....
ON THE OTHER HAND, she was the sweetest most loving caring person in the whole world...to take in a 3 year old when she and her husband were in their late 40's and raise me with so much love and caring....so what if she was a 1/4 yd short here or there !