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Bone Density T Score Calculator

Work out bone density t score instantly with clear inputs, formula shown and shareable results.

About Bone Density T Score Calculator

Expresses measured bone mineral density as standard deviations from the young adult reference mean, the WHO definition of the T-score.

Formula

T-score

T-score = (measured BMD - young adult mean BMD) / reference standard deviation; osteoporosis at -2.5 or below

Worked example

With the default values below, Bone Density T Score Calculator returns T-score of -1.25. Change any input above and every figure here is recalculated in your browser.

Inputs used

Measured bone mineral densityaccepts 0.2–2 g/cm2
0.85 g/cm2
Young adult reference meanaccepts 0.5–2 g/cm2
1 g/cm2
Reference standard deviationaccepts 0.02–0.4 g/cm2
0.12 g/cm2

Results

T-score
-1.25
WHO category
Osteopenia (T-score between -1 and -2.5)
Percentage of young adult mean
85.0%

Step by step

  1. 1Values used
  2. 2T-score
  3. 3T-score= -1.25
  4. 4WHO category= Osteopenia (T-score between -1 and -2.5)
  5. 5Percentage of young adult mean= 85.0

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
  • This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

How does the Z-score differ?

The Z-score compares with age-matched peers and is preferred in children, premenopausal women and men under 50.

Which site is used?

Lumbar spine, femoral neck or total hip; the lowest of the valid sites determines the diagnosis.

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Bone Density T Score Calculator | Calcrivo