Bone density test results are usually reported as T-scores and Z-scores. The T-score compares an individual’s bone density to that of a healthy young adult of the same sex. A T-score of -1 and above is considered normal; between -1 and -2.5 indicates osteopenia (low bone density), and -2.5 or lower signifies osteoporosis. The Z-score compares bone density to the average for someone of the same age, sex, and body size.  Learn more from the International Osteoporosis Foundation