If you’re concerned about your child’s growth, your doctor may recommend a bone age test for child height. Many parents haven’t heard of it before, yet it’s one of the most important tools for understanding whether a child will grow taller — and how much time they have left to grow.
A bone age test doesn’t measure how tall your child is today.
It estimates how mature their bones are compared to their actual age, which predicts future growth potential.
What Is a Bone Age Test?
A bone age test is a simple X-ray of the left hand and wrist.
Doctors compare the image to standardized developmental charts showing how bones normally mature at each age.
Every year of childhood, bones develop recognizable shapes and growth plate patterns. By matching these patterns, physicians determine a child’s biological age — also called skeletal age.
Your child has two ages:
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Chronological age (birthday age)
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Bone age (growth maturity age)
These are often different.
Why Bone Age Matters for Height
Height growth happens at the growth plates — areas of cartilage near the ends of bones.
Once these plates close, height stops permanently.
Bone age tells doctors:
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How much growth remains
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When puberty will progress
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Whether a child is a late bloomer
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Whether growth is slowing early
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Predicted adult height range
It is far more accurate than guessing based on current height alone.
Possible Bone Age Results and What They Mean
Bone Age Younger Than Actual Age
Very common and usually reassuring.
This suggests delayed development and extra time to grow.
Often seen in:
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Late bloomers
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Children who mature later than peers
These children may be short now but grow longer into the teenage years.
Bone Age Equal to Actual Age
Growth is occurring on a typical schedule.
Predicted height usually matches family genetics.
Bone Age Older Than Actual Age
Growth plates are maturing faster than expected.
Seen in:
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Early puberty
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Certain hormone imbalances
These children may stop growing earlier than peers even if currently average height.
How Bone Age Predicts Adult Height
Doctors combine:
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Current height
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Bone age
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Growth charts
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Parent heights
to estimate adult height within a few inches.
Two children the same height today can end up very different heights depending on bone age.
When Doctors Recommend a Bone Age Test
A bone age study is commonly ordered if a child:
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Is much shorter than classmates
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Drops percentiles on growth chart
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Has delayed or early puberty
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Grows less than 2 inches per year after age 5
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Has predicted adult height below family pattern
It helps determine whether to monitor or investigate further.
Is the Test Safe?
Yes. The radiation exposure is extremely low — similar to a few days of natural background radiation.
The process takes only a few minutes and does not hurt.
Why Timing Matters
Growth plates close after puberty finishes. Once closed, height cannot be increased.
The bone age test for child height helps identify whether growth time remains. Early understanding allows families to monitor development appropriately and, if needed, address factors affecting growth while the window is still open.
The Takeaway
A bone age test does not diagnose a problem by itself.
It answers a critical question: How much growth is left?
For many children, it provides reassurance they will catch up naturally. For others, it identifies a need to look deeper into growth signals.
Either way, it transforms uncertainty into clarity.
Learn more about pediatric growth evaluations and height prediction assessments at www.hghforchildren.com.
