Bone Density Calculator
Organize your BMD, T-score, and Z-score information and understand which parts of your DEXA report deserve a closer conversation with your healthcare professional.
- ✓ T-score and Z-score support
- ✓ Transparent calculations
- ✓ No invented fracture percentage
Your DEXA report is the source of truth.
This tool can display report values and calculate a score only when you provide the appropriate reference mean and standard deviation.
Three numbers, different meanings
BMD is the measurement. T-scores and Z-scores are comparisons that depend on the reference data used by the DEXA system.
BMD
Bone mineral density is usually reported in g/cm². The number cannot be interpreted correctly without the scanner’s reference data and clinical context.
T-score
A comparison with a young-adult reference population. It is commonly used for densitometric classification in postmenopausal women and men aged 50 or older.
Z-score
A comparison with an age-matched reference population. It is generally preferred for younger adults and children.
Enter your DEXA information
Enter the scores exactly as they appear on your report whenever possible.
Want to test the calculator?
This fills the form with fictional sample values. They are not medical advice or a diagnosis.
Your bone density summary
Review this information alongside your official DEXA report.
What the scores mean
A score is only one part of a bone-health assessment. Age, medical history, medications, prior fractures, and the scan site also matter.
Normal range
- For the usual T-score classification context, a T-score of −1.0 or higher is in the normal range.
- This does not guarantee that fracture risk is low.
- Your clinician may consider factors beyond BMD.
Low bone density range
- A T-score between −1.0 and −2.5 is commonly described as low bone density.
- Low bone density does not automatically mean high fracture risk.
- Use the report’s wording and discuss the full context.
Below expected range for age
- For younger adults, a Z-score of −2.0 or lower is described as below the expected range for age.
- Z-scores are generally preferred over T-scores in younger adults.
- Children and adolescents need specialist interpretation.
Why this tool does not show a fracture percentage
FRAX is a separate validated fracture-risk model. It uses specific clinical inputs and, when included, femoral-neck BMD. A simple point system cannot reproduce a valid FRAX result.
For an official calculation, use the FRAXplus calculator with your healthcare professional.
Topics to discuss with your clinician
These are general discussion prompts, not individualized treatment instructions.
Nutrition
Ask whether your diet provides enough calcium, vitamin D, protein, and other nutrients for your needs before starting supplements.
Movement
Ask which weight-bearing, resistance, balance, or mobility activities are appropriate for your health and fracture history.
Medication review
Review medicines that may affect bone health and never stop a prescribed medicine without medical guidance.
Fall prevention
Discuss vision, footwear, home lighting, balance, and other practical ways to reduce fall risk.
Follow-up testing
Ask when repeat testing is useful for you. Timing depends on the result, treatment, age, and clinical situation.
Prior fracture history
Tell your clinician about fractures, how they happened, and whether they occurred after a minor fall or injury.
Have your DEXA report ready?
Enter the values exactly as printed and use the summary to prepare better questions for your next appointment.
