Why Your Height Changes During the Day and With Age

Your height is not one fixed number

Standing height can differ by a small amount depending on when you measure and how old you are. Neither change is unusual, and both are well described in research.

Morning to evening

The discs between the vertebrae of the spine are cushions that compress under the weight of the body while you are upright, and they recover partly when you lie down. A study in the British Journal of Sports Medicine reported a mean circadian variation in stature of 14.4 mm in male subjects. The same paper observed reversal of spinal shrinkage during a night’s sleep.

That is a small study of men, so treat 14.4 mm, about 0.6 inch, as an example and not a rule for everyone. Individual amounts vary.

With age

A 2025 paper in Frontiers in Endocrinology, which studied height loss in Chinese adults over 40, cites findings from the Baltimore Longitudinal Study of Aging in the United States: height loss begins around age 30 and increases with age. From age 30 to 70, cumulative height loss averaged approximately 3 cm (about 1.2 inches) for men and 5 cm (about 2 inches) for women. By age 80, those figures rose to 5 cm for men and 8 cm for women.

The paper lists several contributors, including narrowing of the vertebral discs and aging of bones, muscles and joints, and it links osteoporosis-related fractures to height loss.

• These are averages, so individual change can be smaller or larger.
• If you notice a sudden or large drop in height, talk with a doctor.

How to compare fairly

When you compare your height with someone else’s, or with your own earlier numbers, measure at the same time of day. Use the same spot, the same posture and the same method each time.

Heights listed on a profile or form may have been measured at any time, in shoes, or years ago. The comparison tool draws whatever numbers you type, so the result is only as consistent as the numbers you enter.