Measuring your chest width ensures clothing fits correctly and helps track changes in body composition or fitness progress. The term “chest width” usually refers to two measurements: the full chest circumference (standard for clothing) and the less common flat width (used in detailed body analysis). The circumference captures the entire girth of the torso, while the flat width is a straight-line measure across the front of the body.
Essential Tools and Preparation
To achieve accuracy, use a flexible, non-stretchable tailor’s measuring tape. The subject should stand upright with a naturally relaxed posture, avoiding slouching or puffing out the chest. Take the measurement on bare skin or over a thin, non-compressive base layer, as thick fabric distorts the reading.
Keep the arms resting comfortably at the sides; raising them shifts musculature and inflates the measurement. For best results, enlist a partner to ensure the tape remains level and properly positioned around the back, eliminating the error of misaligning the tape while reading it yourself.
How to Measure Chest Circumference
Chest circumference is measured at the broadest part of the torso. Position the tape measure directly under the armpits, passing across the shoulder blades in the back and wrapping around the front, typically crossing over the nipples.
The tape must be kept strictly parallel to the floor to prevent skewing the final number. Instruct the subject to breathe normally, taking the reading during a relaxed exhale or a mid-breath pause; never measure on a forced inhale, which expands the rib cage.
The tape should be snug against the body but not pulled so tight that it compresses the skin or tissue, ensuring a true representation of the body’s relaxed volume. This measurement is used by tailors and garment manufacturers for suit and jacket sizes.
Ensuring Accuracy and Flat Width Measurement
Achieving a precise measurement requires checking the tape measure to ensure it is not twisted, as a twisted tape shortens the measured distance. Verify that the subject’s arms are relaxed and they are not hunching their shoulders forward, which artificially reduces the circumference.
Bi-Axillary Flat Width
For body composition tracking, the bi-axillary flat width monitors muscle development distinct from fat gain. This measurement requires a straight-edge ruler or specialized anthropometric device. It measures the straight-line distance across the chest from one armpit crease to the other. Unlike the circumference, this measurement excludes the curvature of the back and focuses on the side-to-side breadth of the torso. This straight width, combined with the circumference, offers a fuller picture of the chest’s shape, useful for monitoring changes in pectoral and latissimus dorsi muscle mass.