The manufacturer should list the dimensions of the bag. Measure your guitar to verify that it fits those dimensions. First, measure the body length. This is the length from the bottom of the guitar to where the neck meets the body. Also, measure the neck, and then take an overall measurement of the length of the complete guitar.The width is a bit trickier;and consists of three unique measurements: the lower bout (typically the widest part of the guitar, near the bottom of the instrument), the middle bout (the width across the guitar where the sound hole is located), and the upper bout (the width just before where the neck meets the body).