First, how is the size of the guitar calculated? 1 inch = 2.54 cm 1 cm=0.39370078740157 inches The size of the acoustic guitar should be from the top of the head to the bottom of the box: 39 inches, 40 inches, 41 inches refers to inches. 1 inch = 2.54 cm. 41 inches (inch) = … Continue reading How is the guitar size calculated How many inches of guitar is best for you？